I find hard to believe that we'll be getting more companions and Larian haven't make that a selling point or at least one of their ''longer cinematics than the entirety of game of thrones'' statistics... If there's more companions good but I won't be holding my breath.
This is just my theory.
I think it could be because in 1 case they don't want to reveal too much about the Companion yet, because its The Guardian you build in character creation, the one encouraging you to use your tadpoles.
And the other I think is Alfira who I think is very touch and go as to weather she will be ready in time for full release or she'll come in a later patch, they don't want to get folks hopes up.