Will Mirrorless Replace DSLR? - Concerns about Upgrading

So, I'm pretty new to photography, and I feel like I'm coming into the world of DSLRs right as the market seems to be transitioning to mirrorless. I'm concerned because I want to get more lenses for my Nikon D3300, but it seems that the future of the F-mount may be a bit uncertain. From rumors, it seems that Nikon will discontinue many of its DSLR models and replace them with mirrorless cameras. I would really like to step up to the D7500 or it's successor (since that seems to be one of the cameras that may get one), but I'm concerned about that if I continue investing into the F-mount, there aren't going to be any cameras compatible with it in the near future. I'm aware there are adapters, but as of yet, the only decent one for F-mount is for the Z-series and it's $250 (on top of the very expensive price of the camera). I'm not necessarily opposed to moving to different mirrorless system now because I don't have much invested in my setup, but there aren't nearly as many options for lenses currently, and they all seem to be much more expensive than a lot of DSLR lenses. I am also weary of buying new lenses because if Nikon focuses exclusively on mirrorless, the value of older F-mount lenses will probably fall drastically. I'm curious to see how Nikon's introduction of cheaper mirrorless cameras will influence the market (it should bring out some cheaper mirrorless lenses), and what they're going to do for APS-C, although I doubt they're going to put much effort into legacy support.

P.S. I also like the chunkiness of DSLRs and I'm not that fond of electronic viewfinders. Even the one on the Sony A7RIII was a bit disappointing; it didn't look that great and I was a little saddened to find that the color balance was severely off (and yes, I know you can adjust that, but even still it was never great).

I moved mirrorless and know a number of others who have too.  I also know some people are waiting for a couple more years before making that jump.  Nikon should have a Z5 coming out soon.  So the rumors say.  

Yeah, I'm really interested in the Z5. We'll have to see though. Oh, and the D7600 (which is rumored to come out by the end of the year too). Maybe that'll be good enough that I wouldn't mind holding on to DSLRs for a while.

The only chance I would invest in a mirrorless
is if I'd get more jobs where silence is required
and that seems unlikely.

So I'll go on with my trusty DSLRs.

Sticking with DSLRs will be quite difficult if they stop making them.

I don't see that happening now, but certain segments will probably change...

You're talking about Nikon, I seem to recall seeing an article talking about how Nikon seems to be showing more interest and direction towards mirrorless than DSLRs.  

Mirrorless is the future, but DSLRs won't stop working because of a new product. I'm sure when I finally get a Z whatever, I'll keep at least one DSLR in the bag....Its a good choice and should cause no anguish. 

New but trying wrote: Sticking with DSLRs will be quite difficult if they stop making them.

I don't see that happening now, but certain segments will probably change...

As long as they sell, they'll be made. Lenses don't wear out (they get mistreated) and nothing prevents one from using lenses made 20 years ago. In a DSLR, the only thing that wears out is the shutter, and that can be replaced.

DSLRs have a good life, still, IMO, which will easily take us to the point that mirrorless models are comparable. At which point, you'll likely find adapters on the used market, too.

Don't worry about the future; it will take care of itself. If you want a camera, buy one based on what's available today.

I, for one, have never regretted my choice of Nikon, and am on my third body.

Yeah, that seems like sound advice. Cameras are so good, by the time I'll want to upgrade, there will probably be cheaper adapters and cameras. It's definitely gonna take time, but I'm interested to see what happens. Also, B&H has refurbished D7500s for $600, which seems slightly insane to me.

Don't worry, the DSLRs will stick on for a while more. Too many people have invested heavily into Canon and Nikon's DSLR systems for them to switch focus completely to the mirrorless industry. It is true that both these companies are heavily investing into mirrorless cameras, but that does not mean they are ignoring the DSLR. For example, Canon announced both 90D (DSLR) and M6 Mark II (mirrorless) together and the 90D is doing very well. 

Seeing more and more people jumping ship.  I think once Nikon and Canon invest more time into mirrorless, you'll have more people jumping ship to mirrorless.  

Look at how long film stuck around.  If you like DSLR cameras, buy one.  You'll likely find some deals.  1 year from now, 5 years, even 10 years+ you'll be able to easily find lenses.  When you are ready to jump to mirrorless, you always have the adapters that you can use to adapt your older glass.