I'm almost completely indifferent. It's not like he talks much anyways (outside of Alternative Saga) and I imagine they'll keep the Ys Seven system of allowing you to turn off just his voice for that extra traditional touch. Still kind of a weird decision but I'm sure there's a reason.
What I find really interesting is that they seem to be trying to get as much of the original Dawn of Ys cast back as they can. Genda Tesshou and Shiratori Yuri are reprising their roles as Gadis and Leeza (bet you anything someone's going to be acting for two here ;-) ) although Karna and Duren both have new voices... wonder if they couldn't get their original actors? Pity because Ishimaru would have been ****ing awesome but I can't see anything to complain about with his replacement. Less certain about Karna but only because I haven't seen a thing Ogura Yui is in.
Adol talked up a storm in the fully voiced Alternative Saga. On his story route, not only did he have actual dialogue and a lot of it, he even had branching dialogue unlike every other character. On every other route he was back to his usual silent schtick with narration describing his responses. Falcom was clearly having a bit of fun.