It was a goof about how they have a whole video series on building an enormous petabyte media server. LTT is too big for YouTube to not work with them to fix it, and maybe this will nudge them to develop Floatplane into something more than a backup.
Yes, LTT is popular enough to have contacts with YouTube who will help them recover. It's still scary to see a huge channel briefly blink out of existence, and people running less well-connected channels are probably looking at this situation with some anxiety.
The sad part is that there's going to be a few people who got their YT view spammed with the fake Tesla and they unsubscribed. Even with YT reverting the videos/ratings/etc. I'd be really surprised if they reverted the unsubscribes.