Traveling on 12/18 from DCA-PBI, when tickets were booked myself + 6 others were on a mainline A319. However, when checking on the reservation today it's been switched to a E175 operated by Republic. Just curious in this case, would US let me reroute back to a mainline flight?

I'm not worried about comfort as the E175 is one of the nicer regional jets out there (2+2 works better for the family anyway), I'm just concerned about the flight being canceled in case of Irrops.