In a way I think the manager will be pleased that so many will be out of contract and he can sign the players he wants to work with. I don't really think it's a bad thing, a big clear out is perhaps needed. It'll be the first real opportunity he'll have had to assemble a squad of players that he thinks can fit what he wants to do.
My only concern would be the lack of money he'll have available to spend.
There's no guarantee that he'll get it right of course, but that would be the same for any manager.