It always was, holo never had an official bilibili channel even before the yab.
What happened was some subber made it, got popular demanded holo to work with them
Holo went: Ok bro just do whatever
When the holo yab happened, the subber guy deactivated the account threatening hololive. Holo went: Ok bro just do whatever.
He reenabled it like a year ago. Wayyyy before this matsuri thing.
@Gaotye (bilibili DD) thinks it's gay op from bilibili itself to reacquire the channel and not the original subber.