First things first: warts and all, I want Jaylen to retire a Celtic. He is an absolute gamer and is always willing to be the 1A when Tatum is either out or ineffective, although he is not quite as consistent as Jayson in that role (passing and ball-handling are just a notch below what is needed). Any off the court items I disagree with - general agreement with Kyrie on social issues and association with Kanye are the red flags in this regard - do not in any way affect his on court play. Unlike Larry Legend, whose off the court activities of doing his own hard labor I could care less about but DID mess up his back. Or his cohort Kyrie who was willing to sit out games to prove a point. Let me be clear, POBOBS will patch a nice supporting cast together even with 2 Supermax spots taken and I want to see this happen!
As for the upcoming situations and each side's interests, it is easy if Jaylen gets the Supermax:
JB = Dumb if he requests a trade before signing the Supermax. Would throw so much money out the window for only a slightly advanced departure from Boston. The modus operandi for players now, is to sign the Supermax THEN ask for a trade once they get through the first season if unhappy. And with Tatum's supermax kicking in around the time of one year after Brown's, maybe it would be a mutual beneficial decision for both parties to go in different directions at that time (later rather than sooner).
Celtics = Dumb to trade Jaylen before the Supermax. You will not get a great return for JB with a year or less left on his contract, and if you just wait until the ink dries on the future contract he has 4-5 years of cost certainty for a new team, making him much more attractive as the cap likely continues to rise. Unless you are an absolute albatross like Russell Westbrook, these high contracts are never as tough to move as anyone thinks before it happens.
If not getting the Supermax:
JB = Getting a trade before free agency only helps him make an informed decision i.e. a "try before you buy". Based on his recent interview, Jaylen doesn't seem like the "lifer" type who puts excessive thought into staying with one organization. So in that respect, this is consistent with his thinking, especially if money is not a factor. Being traded also gives you a better out from the city than if you outright sign with another team in free agency; there is some degree of separation.
Celtics = Wise to at least kick around trade opportunities rather than waiting for a free agency period and none of "us" (fans and probably front office) really knowing what will drive Jaylen in making his FA decision. Without Jaylen, the surrounding cast for Jayson will still need a clear sidekick rather than a bunch of mid-level guys, and instead of having nothing trading JB gives you a crack at a (probably) small downgrade from him, or gives you future swings to hit on a premier draft pick.