Since the D7500 is not the successor to the D7200, what is it?! Well, as I read it, Nikon decided to make a crossover, a hybrid if you will, of their top two crop frame cameras. Combine many of the features of the D7200 with many of the features of the D500 and what do you get? The D7500.
I personally own a D7200 and a D500 and if I had the choice between the D7200 and the D7500 and cost wasn't a major factor, I'd strip away the 7 and get a D500. It is that good of a camera and it's not really all that expensive.

Warn them about what? That in a few years there will be fewer choices of DSLR'S!? What real difference would that make? What?
The DSLR Doom and Gloomers are either looking for ways to justify spending money on a new camera body, when no justification is needed, or, they simply have way too much time on their hands and instead of going out and taking photos, would rather sit behind their computer and announce to all that will listen, or more realistic, read, how much smarter they are for having seen the future and jumped on the MILC band wagon.
Like most mortal beings, I cannot see into the future all that well. The technology that makes MILC'S a viable option is coming along quite nicely. That doesn't mean DSLR'S will suddenly just stop working! Does anyone believe the manufacturers have designed a tiny nondescript circuit into their DSLR battery chargers, and one day a signal will go out telling all those chargers to stop charging?! Or something equally nefarious and effective, to suddenly end the lives of hundreds of millions of DSLR cameras, just so everyone would now have to buy something without a mirror in it!?
So back to my original question, warn them about what? Realistically, DSLR'S and MILC'S basically do the same thing, with a few technological differences, but ultimately they gather light and focus it onto an image sensor and store said I'm age in a digital format.

Mirrorless cameras predate DSLR'S so I don't see what the big deal is. And before everyone responds in disagreement, what the vast majority of people refer to as mirrorless are MILC'S. Any camera without a mirror is mirrorless. My Canon G1X III is mirrorless. My Canon M50 is mirrorless but it's an MILC.
As for a beginner camera, does the beginner want to learn Photography or just take photos!? Anyone can get any kind of camera and put it on auto and go out and get decent photos. Using a MILC on P or A or S or T or whatever the manufacturer calls it mode, can actually "dial in" the photo with the cameras Electronic View Finder. Is that really learning Photography!? Maybe not but it will also result in decent photos. Learning about exposure and the interaction between ISO, aperture and shutter speed can be done on a MILC but it's maybe a little tougher on a DSLR. If the beginner is only interested in decent photos, something better than a smartphone camera will allow, a good point and shoot or bridge camera, mirrorless as they are, will probably suffice.
My suggestion for a good beginner camera for someone who wants to learn Photography and doesn't mind changing lenses is the Canon M50. It's easy to learn and use, teaches camera discipline and is capable of excellent photographs. For someone who wants something a little larger, a Canon T6i or a Nikon D5600.
Personally I don't believe DSLR'S are dead and yes I believe MILC'S are the future, just not those tiny little ones.

I use the EF 85 f/1.2 for portraits. If you're going for shallow depth of field and super bokeh, get the EF 50 f/1.2, you won't be disappointed.

I use Op-Tech straps on all my cameras and heavy lenses. Each camera body and heavy lens has the Op-Tech quick disconnect connectors on them so I can use whichever strap or harness I choose at the time.

Ha ha, I've got your decaf. Besides, you know me well enough that if it doesn't have caffeine (coffee) I'm not drinking it.
When do you want to go riding? Have you gotten kitty back on the road yet. I really like your new bike. Now I want one, but it's just not in the budget. Besides, mine runs perfectly fine.

So where do I find one of these cameras with the higher KPS rating?

Let's assume you didn't read our friend from Western Canada's response that my response was directed at and based on. That would explain, at least to me, why you felt it necessary to correct me, even though I was not in error in the first place.
If you actually took the time to read xt2's response that I responded to, you'd understand where I'm coming from.
First, let me say this, "DUH!?". And being that I was born in Philadelphia and reside in a Philadelphia suburb, you get why...
XT2 mentioned crop and full frame formats and mirrorless as a format in the response I responded to. Also take into consideration, the conversation is about 35mm digital cameras. Also, based on your response to my response, there are various sizes of APS-C sensors. Nikon's 1.5 crop and Canon's 1.6 crop to name two.
Ok, here is why I'm right, XT2 only mentioned the two aforementioned formats and mirrorless. Mirrorless, why does everyone say mirrorless?! We all say DSLR, so what's so hard about saying MILC? All cameras, including cell phone cameras, that don't have a mirror are MIRRORLESS!
Anyway, xt2 mentioned crop, full frame and mirrorless and included mirrorless as a reference to a image sensor size format. Go back and read the response I'm referring to. My point is, mirrorless is not a reference to image sensor size or format. My reference to three formats was in reference to the actual two formats referenced, and the third, mirrorless, which really isn't a format at all, when referencing image sensor format sizes. So, you can now clearly see why I said three formats. It's pretty obvious, even to someone from Philadelphia, and remember, I'm from Philadelphia, that I wasn't saying or implying there are only three image sensor size formats. Got it? Good.

All three formats!? Ok, there's Full frame and there's crop frame. What is the third format???
MIRRORLESS, (or more correctly MILC'S, since any camera without a mirror is mirrorless), is a reference to what's in front of the image sensor, it is not a format.

I'm sorry, I just had to reply to this one. I've been reading all the replies and wasn't going to comment until I got to the end but this one...
Why would she check out a D7500?! She owns a Canon and Canon lenses. How many of her Canon lenses do you actually believe will work on a Nikon D7500, how many?! Did this guy even read the OP'S original post?!

Correction, the Midway is in California, the USS Intrepid is in New York.

I don't believe he had any accommodation on land, just lived on board the destroyer. He said they sailed the east coast of the USA from New England to Cuba, back and forth. Would stop in Connecticut, New York, Philadelphia or Norfolk along the way. Sounds kinda boring. He served on three other ships, the last one was the aircraft carrier USS Midway, which is now a museum ship in New York.

If you want a full frame camera you don't need to justify it by getting advice from the rank and file, all you need is the money to pay for it. My personal opinion of the photos you posted, only the first one would really have benefited from full frame. But, it's not really a matter of need, it's more a matter of want and if you want a full frame and can afford a full frame then get your self that full frame.

I have both full and crop frame DSLR'S. I use a full frame for my daily shooter and crop for more specific shooting.
Right now Canon has the body you want refurbished for a few cents under $1300 USD, not a bad price for 26 megapixels, a digic 7 processor and a fully articulated touch screen; and if you don't have enough cash, Canon will finance it interest free for 12 months, which would be roughly $114ish per month with tax. This way you keep your 70D, I've got one and use it often, and get that 6D mk II you want. Heck, I just might buy one.
As for the EOS R, it's a good camera but it's also the first of the new generation of FF MILC'S from Canon, and I personally avoid bleeding edge technology. Wait until the technology matures a bit more. What's good now will only get better in the future.
Bottom line, you've got the info you need, now go for it...!

One thing that I've often wondered about and we've talked a little about, but not a whole lot, is why he joined the Navy in the first place. He's more of an Air Force kinda guy. Aren't most Navy personal assigned to ships? He's not what I'd call a ship board guy, not even a big ship, like the last ship he served on, the USS Midway. He was on a destroyer when he went to Cuba. I don't recall the ships name but I've been on a destroyer and they can be pretty cramped, and he does not care for cramped at all. We have a small bathroom downstairs and we won't use it with the door closed, too small, confining for him. I can't imagine him sharing one of those 2 by 6 bunks with another person either. And according to him he's been claustrophobic as long as he remembers.

Looks like fun...!