It would make sense to recommence SEN-DUB in October as a replacement for some of the current new routes which will not operate over the winter period. As to whether this will operate under the Flybe brand or Aer Lingus Regional I guess that may depend on the attitude of Aer Lingus towards adding a jet to the AER fleet. The existing codeshare between Flybe and Aer Lingus may enable through bookings to US destinations if flown under the Flybe brand.
Flybe's previous animosity towards SEN-DUB would presumably no longer apply since they ceased operating LCY-DUB.