Clearing out the older players just weeks after getting there? Which manager actually does that? Pellegrini didn't do a clear-out, neither did Moron. In fact, Moron hasn't ever done that as far as I can remember. Heck, even Wenger didn't do it when he arrived. I am sure he wanted rid of the old back 4, but did what most managers actually do - he gave them a season to prove themselves.
Honestly, it is THIS summer which will show what Moyes is made of, and he has been helped by players like Giggs, Evra, Vidic and Ferdinand all being on outgoing contracts. He could have renewed those contracts of course, which would have been hilarious, but it is a massive help getting rid of them this easily.
Sure, Moyes has performed quite a bit below par with the squad he has, but I certainly would have been VERY surprised if he had done a clear out like that last summer.