While I agree that I do like the voice acted battles, I'm pretty sure a QA with Yoshida about it would look like this:

Interviewer: There are many icon battles in XIV that have wonderful voice acting that adds to the experience of the fights. Can we look forward to more battles including this in the future?

Yoshida: Voice acting is really expensive, even for a few small lines, so if we were to include more of those then we would need to take money from other places which could negatively impact the development of other content.

Interviewer: So what you're saying is you'd need more money.

Yoshida: Hai.