>>75570349I think it's more likely they're waiting until they have a new wave lined up.
Since Xsoleil debuted at the end of 2022, Nijisanji EN has lost 6 talents (Pomu, Selen, Nina, Mysta, Kyo, Zaion), but they've also gained exactly 6 (Krisis + TTT) so the number of vtubers they have breaks even. If they lose even 1 more person, though, then suddenly the number of talents is actively declining. Investors wouldn't like that, because investors want growth.
Once Niji debuts another EN wave, they'll gain some leeway to let 3~6 more people leave without making investors ask too many questions about the sustainability of their turnover rate. I don't expect the graduation queue to start up again until that happens.