Maybe, but unlikely.

They want low fares because it helps keep expectations low with regard to airport infrastructure. Start charging legacy fares and people are going to expect more from the airport, which itself is very lacking from a pax experience standpoint.

Horrible food options and not very many of them (seriously the line for coffee is like thirty deep most mornings). Hardly any lounges. Gate holds for customs during the busy hours because there isn't enough room in immigration.

I could be wrong on this, but if the legacies began to dominate FLL and raise fares to reflect their premium service products, Broward county would have to do some serious "getting their stuff together" to be better in line with the expectations of legacy customers as opposed to all of the half assing that goes on there now.