For the Bills 2 seed...
the Titans can win as long as the Browns come back and win against the Jets (And the Steelers lose the game they’re down 3 scores in...and Buffalo beats New England)
The Bills won’t clinch the 2 seed officially...but they would likely still use next week as a type of bye. The reason for that is:
While they lose a head to head with the Titans...they win the tiebreaker in any multi team tie. So if the Browns come back...the Bills can lose next week and still get the 2 even if the Titans win tonight and next week...as long as the Steelers or Browns win in week 17. The Steelers play the Browns.
as long as that game doesn’t end in a tie Buffalo is guaranteed the 2. I can’t imagine you throw away the opportunity to rest stars because of such a low percentage outcome