Wyc deserves some credit for this deal as well. Many owners would have let the trade exception expire and saved the money. Wyc is willing to pay Thornton his $8m+ salary to get Zeller and a future pick and the payroll is close to $80m for a rebuilding team. It's great to not have a cheap owner.
It's a lot harder for owners to agree to do this if it guarantees the team will play luxury tax.
But of course, in this case, because Bogans' contract is non-guaranteed (until 5 pm Jan 7 at which THIS season would become guaranteed), they can easily, at any time before that, shed 5.3M off the books in order to drop below the LT threshold (which should be around 77M, I think?).
So long as they are below the LT threshold at the end of the season, they can avoid the tax.
Since it may still come in handy to facilitate some other deal, I expect they'll keep Bogans on the roster up until then (Jan 7) unless a deal manifests earlier that would make use of his contract. In the mean time, it would suck paying him to play golf and he would cost a roster spot, though.