A sorcery-speed spell wont do much when your opponent casts Entomb and Reanimate in the same turn
Ultimately, however, with so little revealed so far, well just have to wait and see what spoiler season brings up for this mechanic
Turning the targets into treasures is certainly a drawback since it gives players the option to turn their useless card into mana, but ironically players will often crack their treasure and lose the opportunity to get their card back when Kitesail Larcenist leaves the battlefield
Then, other non-human creatures you control get +1/+1, so your ghouls already out are getting buffed, and on top of that, they have undying, meaning theyre resurrected with a +1/+1 counter if they died without one
Or if you have decent offers in mind, PM me and Ill pass it on to the guys who own the playtest cards