Ainge has just about reached the limits of the asset-collection phase of the rebuild, and he has a really nice collection of supporting players. He must know it is now time to focus on exchanging assets to get a couple of real stars.
I don't see the C's staying put with their current picks, because the chances of nabbing a star are small. We aren't really building more value by adding more solid contributor level players at this point.
I think he knows there are players with a realistic chance of becoming superstars in this draft: Okafor, Towns, Russell, Winslow and maybe Mudiay, and a super role player in WCS that would help almost as much as a star. I see us either trading up for one of these guys, or trading the choices.
Crowder is a very nice player to keep, but Ainge knows his priorities and will move him if he has to to get a star.