Yes, I would object it. I hate AI voices with a passion, it's soulless, and I never asked for my character to have voice acting.

The only case where I had a good experience with custom character having voice lines is in the game God Eater 1, where your character is also quiet the entire game for their voice lines, and only have grunts and laughs for emotes & combats. Then at the finale, they have every 1 single spoken line for climatic effect done with your chosen voice (and was acted by an actual voice actor of course).

I'd rather they do something like that, than having AI voices

The moment AI voices appear in FF14 is the moment my opinion of CBU3 go down, along with Square Enix