Unless Republic plans on learning how to fly -900's, they will not be an issue in taking the flying, as scope will not allow any more 70+ seat aircraft on property. Air Wisky got a contract extension for the money they gave airways, so any additional flying would not be a mandatory thing (even though they would be a good choice from a pilot perspective since they would fly them for good pay). I personally see some -900's going away because USAPA wants to regain scope and there are way to many RJ's in the system in relation to mainline aircraft, and what is left being jet-wise being split between Wisky and PSA.
DISCLAMER: ALL SPECULATION!