What would 50, 60, 70 year old Kevin even be like? He's both emasculated himself and crippled himself (in every video of him he clearly can't walk properly, and if that's not healed by now it's probably permanent), in the all-too-depressingly familiar story of fetishists getting into more and more extreme stuff for a coom. He has nothing to put on his resume (2019-20xx - Tenacious Unicorn Ranch - Played Overwatch. Also responsible for posting revolting personal information on Twitter. Masturbated a lot.) Even the most cursory search of either his old or new name results in a tidal wave of lazy, revolting perversion. He couldn't even get work in a sex shop or tattoo parlour where they generally don't care if you're a massive pervert because he has no work history, no skills, and no work ethic.
Long-term, Kev is fucked. The ranch will fail eventually - it's a financial black hole run by dangerous, insane people and sustained only by the goodwill of strangers and a political trend that lets AGPs get away with literally anything that will not last forever. If the Tranch does turn into Tranny Waco, Kev could end up with the kind of criminal convictions that will cause him serious issues finding a place to live, let alone a job. His inheritance money will run out, and he hasn't invested a single penny of it - it's all gone on Tranch rent or Transformers toys that depreciate by 95% the second he gets his grubby hands on them.
I guess most likely he tries to get disability or some other tugboat, but where will he go, what will he do? People tend not to let you couch surf once you're past 40 or so, they'll direct you to the homeless shelter instead. I doubt he'd have the income to live on his own, he has alienated his entire family, and I doubt any of his Twitter "friends" would let him move in given his record of laziness, filth and selfishness, or if they do I can't see them putting up with him for long.
Basically, I think his options will be to turn into a carbon copy of an existing cow:
ADF - gradually becomes more and more homeless as the number of people allowing him to couch surf dwindles, probably buries himself in some shithole anarchist commune. Maybe becomes a crazy old man living in the woods or the homeless shelter. I can't see Kev accepting such a drastic reduction in his creature comforts though, and most communes will expect him to work.
Tommy Tooter - The drug abuse gets to him and he loses his grip on reality entirely. He finds some favourable rent terms in some cheap shithole and becomes a crazy hoarder. This is dependent on him finding a place to wedge himself and managing his finances better than he currently does, which would require a degree of forward planning, intelligence and initiative that we've never seen from him thus far.
Panzy Gronski - He teams up and moves in with someone just as perverted as him and grows old as a feminised eunuch. His "mxtress" would have to be wealthy enough to accommodate him and actually get off on Kev being pathetic and useless. Whilst this would be materially the best outcome for Kevin and the only one where he doesn't starve to death at 60 surrounded by filth, I'm not sure Kev's ego would be able to accept becoming an actual sissy slut slave despite what his one-handed Twitter tirades would suggest. I don't think he really does have a humiliation fetish, he just thinks he ought to have one so he can flex his fetish collection the way he flexes his transformers collection.