That looks about right for the Celts.
Best case scenario I think the team wins low-50s. I could also see them ending up closer to 45 if they struggle with injuries, the bench struggles to score, or they just have bad luck in close games.
As for other teams ... I like the Mavs to get to .500 once again. I think the Hornets will be decent but not great again, if MKG, Kemba, and Cody Z stay healthy.
I believe the Raptors are winning 50+ again with the same basic core plus a healthier Carroll.
I believe the Kings will be a disaster given their excess of bigs and dearth of points guards or defenders.
I like the Heat to make a run at the playoffs even without Deng, Bosh, or Wade, because I respect Spoelstra.
I expect the Bulls to be closer to 30 games than 40. Terrible roster makeup and the chemistry will be bad from day one and only get worse.
I think the Thunder will have to fight to stay at .500 all season.
I don't expect the Knicks to win more than 35 games. They'll head into the season already in controversy thanks to Derrick Rose, and that starting lineup cannot possibly stay healthy all year. They still don't have very many NBA caliber players.