Yeah, as much as I'd love this I think it's never going to happen; the player character has probably thousands of lines of dialogue to choose from, if not tens of thousands with all the unique options for each class etc. There are eight different voice options for custom characters (but this is for mostly incidental dialogue, like detecting a trap), and then there are six uniquely voiced origins. It's not impossible to do it but that's an enormous amount of dialogue they'd need to record, and it would be a lot of audio files to add to an already huge game.
I am not asking for Tav to have voice acted lines. I am asking for my OG character to be voice acted when I play as an OG character. It's a much smaller amount of lines to do per voice actor. I don't care about Tav being "mute" when I play Tav. But I would like to do a playthrough as Astarion and have my lines voice acted. I think it would greatly enrich the experience for me.
And I know it probably won't happen... But it doesn't hurt to dream about it! And if the devs like my dream, they might make it come true some day!
In any case, I think we've been further from this being the new tradition, now that we have chatgpt. There was a time when none of the dialogue was even voice acted. You had to read everything yourself. Then they added voice acting for OG character. I think the easiest next step is what I'm requesting. And probably after that, they will add voice acting for Tav too.
Doing a playthrough as Astarion without hearing him speak and without his mannerisms and facial expressions is like playing a ghost of the real Astarion we experience as Tav. As if someone took his soul and his very essence from his body and left us only the shell of Astarion to do the playthrough with.
Like I said... I'm just dreaming... and wishing... and maybe even hoping...