These planes are most likely replacements for the A318. the 318 financial dynamics did not pan out as expected for Frontier and they stopped ordering them. There is a need for a 120-130 seatish plane, but the economics of the 318 just were not there, I understand. I would expect Frontier to fly them, and depending on any agreement with the YX pilots, they might get them too. Or, they would just be branded with the brand that survives any brand consolidation.

And, Pigeye01, I don't see 'Republic" as the brand. There is no name recognition with the public for such a brand. There is a lot more recognition for either Frontier or Midwest.