The issue is that it would be very very expensive. Think about it, the game doesn't just have a standard 1 male and 1 female. Different races may sound different, and then we add in Origin characters (I dislike origin characters as PC but it's in the game). They would have to record every single companion character being used as PC on top of standard customized character.
In 2021 you would think this being doable with some kind of sound engineering software tech that filters a single voice into many types.
