Uhhh, you do realise Mike Morhaime retired several months before Classic Beta launched, don’t you? He’s had very little, if anything to do with Classic’s development.
OT: Layering is a big problem, that we all know by now. Unfortunately the only way they could avoid using it would be to open double the amount of servers they currently intend to and merge low-pop realms after phase 1. And that’s simply not something that Blizz is going to do.