1.) He wasn't originally committed to Tennessee, so his initial commitment wasn't as affectionately arrived at like someone like JJJ, Grant Williams, Admiral Schofield, etc. He was rushed thru the process after decommitting from Marquette.
2.) He almost left last year, so doing it this year isn't quite a shock to his system. In his mind, he's already processed this decision once before, just with a potentially different outcome. In other words, he's already pictured in his mind what it might look like to be somewhere else.
3.) He holds the cards against Tennessee, now. He's our only experienced big man returning. He likely wants to be compensated for the value that status brings. If he's getting an offer elsewhere, I can see why he'd want to maximize that value.
4.) He might see a better path to a F4 elsewhere. The reality is that we lose a lot of production. Betting on Tennessee requires a bit of faith at this point. Saddling yourself to Duke or UNC offers a more certain path to his last shot at a title.
5.) He may be at odds over being pulled in the final game of the season. That may not have set well with him and so it may be a Chase Burns situation where it's best for all parties to go separate ways.
It could be any or all of those things. Nothing surprises me anymore. If Mashack bolts, too, I honestly wouldn't then be stunned to see ZZ hit the portal after he looks around at what remains of this team (himself, 3 freshman and Gainey) and decides that he's got little connection to anyone left and his services would be highly sought after by a major contender willing to pay him big money.
The portal sucks. NIL sucks. But we all saw this coming. It's ruined college sports.