@planespeaking the change to Flybe on the DUB route does not affect use of US pre-clearance which is used by all US departures from Dublin regardless of what airline. It will just mean transferring from T1 to T2 at DUB (an easy walk - both are linked airside)
Are the connecting flights bookable though? Aer Lingus is still showing any flights from SEN to US destinations as unavailable after 25th October and the first flight from SEN to Dublin appears to arrive too late for the westbound transatlantic flights.