And in the name of returning to original topic ...
How would you feel if we were given K. as a Fighter "for now" ?
Dunno what is holding M. back ...
And H. as a something else "for now" too?
(I really dont know wich class is close to Bard)
Bard mechanics are extremely unique. There's really nothing in-game that would convey an acceptable placeholder substitute. Maybe Wizard if you're really stretching. There's a reason not even Solasta has touched Bard yet, and everyone there is also assuming it'll be the last class added.
I don't think Helia is staying as a Bard. Her assumed transformation mechanic seems like it'd be far better suited for Barbarian, Monk, or Druid. Especially considering Bards revolve entirely around how well you manage their action economy since they have a lot of shit they can do, a transformation mechanic on top of that would make things weird.
I hesitate to say Druid though because I get the impression Halsin may be retooled into a proper companion. Alfira could end up being retooled into a Bard companion too.