I don't think he'll change any of the numbers when players are still here so my guess is the new players will all take departed players numbers. At a guess I think Gueye will get 8, Richards 4, Bunn 31 & if Amavi signs he'll have 19 as its his current squad number.
I think out of current players only Grealish will get a new number as I think Tim will give him the 10 shirt now it's free.
I agree with what others have said though, Sinclair having 9 and Baker having 2 doesn't sit right with me and I hope the numbers get shifted around, but I don't think they will