Well, from the "could he be dealt" standpoint, anything is possible. Aside from a few players that have a contract where the dead cap would be unmanageable or a no trade clause, of course. There is a "purchase point" on almost every NFL player where if a team exceeded that point in an offer and the contract was doable...anyone is for sale
So that would beg the questions, what would another team view his value at and where does Beane view his worth? If a team wanted to throw something ridiculous at the Bills...say a 2nd rounder then they would have to seriously consider that. And I don't see that happening.
At the end of the day I believe he's worth more to the Bills 2023 (and beyond) plans that what they would get in value from a trade. Even if he didn't actually beat Dane Jackson out (I believe he did) he will likely see some significant snaps and some starts this season IMO.