I could see it happening if the range on the 737 max is up to scratch. Feed everybody through Shannon on this side, pre clear them and fly them to less mainstream airports in the north eastern U.S.
Somehere like Pittsburgh would probably jump at the opportunity where PAX numbers went from 21 Million in 1997 to 8 Million in 2012.
Making it 2 separate flights where you don't interline means APD is only from Ireland...............lets see would Irish Govt say not to continuing low APD for an extra million or two passengers through Snn ?
Reason for NO interline is that when you do then home country can claim its a T/A connecting flight and try and charge you accordingly. Any APD experts may be able to clarify.