The Girl Lost in The Burned Tower

Whilst this is probably true, it doesn't explain anything in-universe. Now the DeadRed Theory, that explains his dissapearance on defeat, in-universe.

You're doing it again. The DeadRed theory is an attempt to explain Red's actions in-universe which, by their nature, cannot be disproved with out-of-universe reasons (like lampshading Black-outs). Please hang up and try again.

If its true, then it doesn't need an in-universe explanation.

Do we require an in-universe explanation for Game Freak's existence, and their dialogue claiming to create you? No, because that's breaking the fourth wall to make a shout out. It's the same case with Red.

People are only making up these theories because they can't accept that its just as simple as that. An in-universe explanation doesn't need to be given for breaking the fourth wall.

Also, I'd like to take this opportunity to point out that DeadRed would serve to explain not only black outs and why no one's heard from him in ages but how he can just sit at the peak of a lonely, freezing-cold mountain peak forever with no extra clothing.

I'd like to point out game-play and story segregation as the reason for that because it validly explains everything as well. I've given an explanation for everything else, as for why he's only wearing those clothes in a blizzard?

(1) In the original games, the peak wasn't shown to be a perpetual blizzard, so he didn't need additional clothes.

(2) They wanted to keep is image iconic, rather than updating him like all the other leaders. After all, if they were going to keep him silent and have him "black out", why on earth would you change the most noticeable thing about him? His Gen II sprite after all is just a mirror image and recolour of his yellow sprite.

(3) In the case of HgSs, they added a blizzard, but they clearly wanted to keep his iconic look. They've re-edited everyone, and updated their look from FrLg, even people who wouldn't really look that different. They didn't do that with Red for the same reason as #2

(4) These characters have been able to walk near the crater of an active volcano with no ill effects, suddenly, a little bit of cold, which many characters have been shown in-game to be able to take (Candice, Maylene, Pryce) is supposed to kill him? People always seem to underestimate the resilience of humans in this series. In the very same game, they've had a character rumoured to be strong enough to beat his Machamp at arm wrestling, and we actually see a character get hit at point-blank range with a Dragonite's hyper beam. I don't understand why people think the humans there (which have been shown to actually wield psychic powers) are as fragile as people in this world.

Yes, the theory's also an attempt to explain his actions in-universe, but his actions could be explained many ways (and have, like the pressure of being Champion getting to him etc), but its quite clearly an attempt by most people to satisfy their need to make Pokemon more mature than it really is.

That's one possible explanantion, though don't you find it a bit odd that he hasn't once flown home? I mean, he's only two trips away.

Yes, it is weird, but that doesn't mean he's dead. Why no one's heard from him is yet another joke on being a silent protagonist, as no one would ever have heard anything from him.