To try to eliminate him from contention? Out of everyone at 145 I think frankie poses the biggest threat to the golden boy. 
That would be a shame. He's going to need at least one fight to stay busy though, possibly more. 
I really like Mendes and he's a phenomenal fighter/athlete but he's had 2 shots at Aldo and a shot at Mcgregor and came up short. If Frankie has to eliminate him from title contention then so be it.
Hope not. I think Edgar vs halloway is more fair to Edgar and sets a no 1 contender whoever wins. Even if mendes beats Frankie in 4 sec. A 4th title shot at 145 isn't warranted