No specific plans to must of those shares.
If Toni gets a share, which is not a given, it won't be a male(I'm not saying who to keep the surprise if it does happen).
Joey, as of now, will only be with Zuri.
No plans for Zuri shares. And no plans for a direct Charlotte share.
This doesn't mean the others have a chance to happen, just that it's also not planned at all.
Lana as of now is just Adrian's exposure.
At most, not guaranteed, only 1 more character will join the studio. Undecided who, it will be after a quest.