I wouldn't imagine there is a huge amount of future for Galway or Sligo. Both are too close to larger airports with longer runways to develop serious non-PSO business.
Donegal may be retained as a PSO as there's no rail service to Donegal.
Kerry and Knock are healthy enough without PSO, although Knock might well lose its Dublin service. I would imagine that Kerry-Dublin could support flights to Dublin without PSO. Air offers a significant time saving over road or rail and the numbers are OK. Whether it would still appeal to an airline with 189-seat aircraft is a different matter.