I think out of everyone that's deal is about to expire for the Celtics that the most replaceable is Davis. He has a below average shot, can't dunk, has good hustle, good at taking chargers and a coaches player but replace just because nothing stands out.
With that being said whether or not Ainge brings Davis back will depend on whether or not we get 18. If we do get 18 then I think that Danny will begin the rebuilding process hoping that who he brings in will learn what they can from the Big 3 before they are broken up, I don't think Davis comes back in that case. If they lose then they'll bring back who they can, most likely Green and maybe West but Davis might still be a toss up but Danny just might bring him back. I'd be surprised if he was back but you never know.
Gody would have been a good candidate to replace Davis I do think if he had been better with defense. Not all players are good at defense, heck Melo stinks and he's an all star, but it's important to what the Celtics are doing right now and Gody could score, hustle to rebounds but wasn't good at defense. We'll see what happens but I still don't see him back.