I'm sorry but at the state blockland is in, I don't see youtubers doing much to contribute the lifeline of this game. Let's say hypothetically we got some well known people to play the game some how. First off the content creators themselves really wouldn't have that much content to play in the first place, have you seen the state the master server is in? At best they'd play something like grapple knife with 5 people on it. If there's no appeal to the content creator, than there is no appeal to the audience. I really didn't like saying that because this game still means a lot to me, but I have to be realistic about it, I would love to be proven wrong about this; but this is the way I see it turning out.
Better yet why don't you yourself start making videos for blockland? I've said this before in other places like on the steam pages for blockland, really the only way for a game like this that is this far gone to even consider having a comeback is the original players and audience of the game really trying to make a difference in the first place. Such as making addons, building more new and creative things, community events, hosting fun things again, etc. And it's unfortunate to say but a huge majority of this games playerbase were children who've grown up into adults over the years and are busy with other things than a lego game.