definitely +1 here
I really hope minthara will be a companion at full release
The one hint to Minthara actually being coded as a companion is that she's, erm, stripped to her underwear when you loot the armor off her body. I think she might also carry a camping supply pack, though I am not as certain on that one. An argument against this is that Karlach doesn't get the same treatment, although she is given a different body type that might not be fully implemented yet as far as being armorless goes, and that she was given a subtitle that companions don't really have but certain key NPCs do. Still, having an alternative, evil-er cleric that is probably War Domain to have contrast with Shadowheart would certainly not go amiss, so here's hoping.
Perhaps it's indeed Nere who'd become a replacement for Halsin if you side with the Absolute, or maybe
the drider that Minthara sends you to after the celebration
I also hope that following the githyanki route has its own outcomes, at least for a githyanki character / someone who manages to get into Lae'zel's good graces.