I doubt it will make sense to pay to keep both Bradley and Isaiah, especially if the team also holds onto Smart and drafts Ball or Fultz.
That said, I think it will probably make sense to re-sign Isaiah, because as Boris said, culture and identity matters, and it will be very, very difficult to replace him. I think it'll also kind of damage the good vibes around the team if they let Isaiah walk after he turned into a superstar and the heart and soul of the team within a year after they traded for him.
maybe, but how good will the good vibes be if Boston flames out in the 1st round again (and presumably Thomas has a bad series in the process).
Boston is nearing that cross roads where it has to decide what it wants to be. You can only have and eat your cake for so long before you run out of cake. I believe this summer is that point.
Why?
I've posed this question before, but imagine that three years from now, the team has the following:
Isaiah, on a max deal.
Horford, on a max deal.
Crowder, still making peanuts relative to his value.
Smart, making 15 million a year.
Brown, on a rookie deal.
Fultz/Ball/Jackson/Monk/Tatum, on a rookie deal.
2018 Nets pick, on a rookie deal
Zizic, on a rookie deal
Yabu, on a rookie deal
What's so terrible about that? Imagine as well what Ainge might be able to get at the trade deadline a year from now by packaging Avery Bradley (expiring), Kelly Olynyk (making ~$12 million / year) and non-BRK 1st rounder or two.
I really don't see the problem with ending up with the team described above. Would they be a bit of a mish-mash of declining vets (IT, Crowder, Horford) and not-there-yet young guys? Yes. Would the team be locked into long-term mediocrity or stuck at the bottom of the league with no way out? Heck no!
Even if Isaiah is in rapid decline and Horford is in full-on role player status, you'd still have Smart, Brown, 2017 Nets, 2018 Nets, Zizic, Yabu, and perhaps Rozier or one or two other rookie contract guys as your young / developing core. I am pretty sure that will be a better group than most of the "rebuilding" teams in the league at that point.
I really don't see the urgency you see.
You know what would be terrible?
If Ainge were to go all-in on a guy like George or Boogie, only to have that guy depart for glitzier pastures in free agency after a year or two, and then let Isaiah go along with them because "He's not good enough to carry the team to a championship," or whatever.