Serenity, Coffin Corner, Desk Pilot... All spot on.
People will leave, maybe the majority don't feel the need to fight for anything that the management will drag its heels over and ultimately fail to deliver. Why bother? The slightest sniff of pastures new and they'll be gone. It sounds selfish, but thats life (and the management certainly wouldn't give a toss).
If this is the way the company wants to conduct its business then let them do it. And as for the Training Academy being able to cope, will it? It only takes a few airlines to open the recruitment flood gates and it wouldn't be unreasonable to forecast up to 100 (at least) 3 month notices ending up on a desk in EXT. If that happens before the Academy is opened (or even after for that matter) then cope they will not...