>>75235151Biboo has never specified, but she said shortly after her debut that there is a substantial amount of off-camera work that they do for Hololive. Enough corpo vTubers have said similar things that I believe it's true. They definitely do more than just firing up OBS and the Live2D model and playing today's game.
So yes, like most jobs, people are entitled to vacations for a week or two on occasion. Though in Biboo's case I doubt she's on break, Advent seems to be getting ready for 3D debut.