If it's 3, Bisping, McGregor and maybe Anderson makes sense, regardless of how he does against Bisping.
If it's 4 or more and he loses to Bisping and Bisping retires as he's planning, does he stay at MW and enter some kind of tournament to face Whittaker and crown a new champ? Does he move back down to WW to chase Woodley and maybe McGregor?
If it's 4 and he beats Bisping, does he face Whittaker next? Somehow that seems unlikely.
If it's 4 or more and he loses to Bisping and Bisping retires as he's planning, does he stay at MW and enter some kind of tournament to face Whittaker and crown a new champ? Does he move back down to WW to chase Woodley and maybe McGregor?
If it's 4 and he beats Bisping, does he face Whittaker next? Somehow that seems unlikely.