There's already been A TON that's happened, and I expect a lot more in the coming days. There might also be a lot of 2nd tier players and contracts moved due to impending luxury tax issues, etc.
For the Celtics, my dream has been signing Lonnie Walker and trading for Day'Ron Sharpe.
That said, Springer has impressed me in recent weeks and I think we're better off keeping him for depth and spot minutes particularly on the defensive end when needed, especially when you factor in Jrue's age.
I would have no problem trading Tillman + future 2nd round pick(s) for any of Javonte Green, Daniel Theis or Seth Curry.
Idk if Philly would trade in-division, but if Yabusele is available he'd me my favorite target. He fits everything we need and to his credit, he's done a phenomenal job working his way back into the league and being a real factor. If you can trade Tillman, a future 1st rounder and a future 2nd for him I would do that, but depends if Philly is okay doing that trade to Boston.