When I recently upgraded my DSLR - I gave absolutely zero thought to a mirrorless system, and kind of wish I had. However, I also shoot action (kids sports) in varying light. Having good low-light performance matters to me - a bunch. Shooting with a flash in those situations causes multiple concerns (cycle time, distract subjects)...
I upgraded from a D90 to a D500 and am completely ecstatic with it. However, it IS a different interface. There are some controls that are incredibly intuitive, and some that are intuitive, but just different than what I am used to. There are also some controls that are either less intuitive, or so different than what I am used to that I have to hunt. Fortunately, things like WB and ISO are cake. In getting familiar with it, I have probably shot almost 1500 pictures with it in a couple months, and the number may be higher than that.
The low-light performance is so good that I PICK when I want to use flash, not when I have to. Which is also good because it doesn't have a (weak) onboard flash.
The D500 w/ battery grip (which I love) and a decent lens is a LOT of camera to carry. You have to want to carry it, otherwise it will be at home gathering dust while you take pictures with your smart phone. That said w/o the grip, I don't think it is THAT much more to carry than a 7200 or 7500.
In terms of price - refurb/used 7200s are a BARGAIN. They will become even moreso. The 7500 appears to be fairly priced, and the D500 is a bit more of a stretch. With your lenses, you have decent options as a starting point, so you don't NEED to add glass. However, I have historically preferred to prioritize glass higher. I have gone extra years w/o upgrading a camera body to buy better glass - and in the end I feel that it has been VERY worthwhile.
-shooter