I'm actually in the opposite direction - I think Indiana says no.
Hibbert may be flawed, but he's still a career 10 point, 7 rebound guy as well as one of the absolute best rim protectors of the past decade. Zeller is IMHO a small offensive upgrade, and a HUGE defensive downgrade. Even considering his flaws, Hibbert is (IMHO) the better player in this deal.
Throw in the fact that they are also trading down in the draft...and I think there's little chance the Pacers accept this deal.
I'm sure they can get a better return for Hibbert than Tyler Zeller and a 3-spot drop in the draft. If fact I'm pretty sure they could easily enough acquire a free agent center that's as good as Zeller via either free agency or the draft - Zeller really is a pretty run of the mill big man.
Plus most of the $16M they save by ditching Hibbert is offset by the $10M they add by receiving Wallace.