im guessing hes going for a decentralized internet browser, youtube alternative, gmail alternative, and social media. Of course, big quantitation marks would need to be put between decentralized since attempts at this have been pretty lame, see the steemit clusterfuck and other derivatives. If it needs it's own token, it will need to prove the game theory cannot be gamed as seen before. I don't see how Bitcoin fits in all of this beside implementing Lightning Network payments natively, that would be cool, however the Bitcoin blockchain is for Bitcoin transactions, not some Elon Musk experiment.
It would be weird, but it wouldn't be the first one to try it. If there are other social media places in the world, like twitter, instagram, tik tok etc etc, and then he wants to change the world by creating that "x" he is talking about, having twitter and implementing that to the idea would be a lot better.
He could buy out like brave or something, and then buy out vimeo or something, basically the already there stuff, that way he would have a lot of people working on these things, he could buy out telegram or discord or whatever too, so with the chat app, and then he would be able to build them all together in a single thing, it's much better than creating a brand new one of each.