Just looking at the RE fleet it consists of the following:
Aer Arann:
3 ATR42-300 (Each based at IOM, KIR and WAT)
Aer Lingus Regional:
2 ATR72-200
4 ATR72-500
Three aircraft (1 ATR42-300 and 2 ATR72-200) are used for tech duties/leasing. EI-SLM which was involved in the Shannon incident last July has been repaired but remains stored.
If we look at the proposed streamlining of all Aer Arann operations into Aer Lingus Regional and the expected axing of the Isle of Man route to London-City then the fleet should look like this (Including already planned Aer Lingus Regional expansion in May):
Aer Lingus Regional
2 ATR42-300 (KIR, WAT)
3 ATR72-200
4 ATR72-500
This means at total of 2 ATR42-300 and 2 ATR72-200 become available (this time including EI-SLM).
Usually Airline operators keep one aircraft for tech duties, so if that is the expected case 2 ATR42-300 and 1 ATR72-200 would be available for expansion, this could definitely mean a BFS base or more expansion ex DUB, ORK. The proposed Dublin to London Southend route would require another aircraft but that would still mean 2 aircraft are free for expansion with 1 remaining on tech duties.
Looks like there's exciting times ahead for Aer Lingus Regional.