Like Khelgar, you mean?
Personally, I wouldn't expect a variety of voices in EA. Voiceover is expensive and slow process - you hire actors, you rent a recording studio, audio engineers spend their time on it as well, and then devs will have to link clips with their corresponding dialog lines.
The worst thing about it is, if / when a single line changes, you have to go through this entire process again. Not fast, and certainly not cheap.
Unless Larian decides that all dialogs / remarks that involve a particular character are finalised, and aren't ever going to change, only then it makes sense to start the voiceover. And even then, it's cheaper to do all voicing in bulk, so they can save a bit on studio time.
