Those three bidders: Buffalo Sabres owner Terry Pegula (long perceived as the front-runner); the one and only Donald Trump; and a Toronto-based group fronted by Jon Bon Jovi. These are the same three bidders that have headlined the process throughout; apparently, Morgan Stanley has not been able to generate any more interest in the team.
In fact, former Sabres owner Tom Golisano, who submitted a late initial bid earlier in the process, is apparently not going to be submitting a final bid, per Wawrow's report.
Also of note from Wawrow: the final bidding process is going to remain open so that bidders can improve their bids over time, until a final candidate is chosen. That fact, coupled with extensive background checking on the part of the NFL when the final bid is accepted, and it's sounding like the Bills may have to wait until December, rather than early October, to learn who the new owner will be.