The Bills do not have enough "stars" on the team to win without Allen so it's really pointless.
A smart GM would get the worst QB possible as a backup so if we lost Allen since we have no shot, we should get as high as a draft pick as possible that year, thereby maximizing the talent on the team moving forward next year with players otherwise that wouldn't be available for them normally.
Kinda like how Bengals got Jamar Chase.