The deal is the 2700 will return. They will cover Limerick and Ballina shuttle services. The 2700 is for more suited to regional work and may release an ICR or two
This will release the 2800 back to Dublin, that provides all current 4 coach trains at peak to move to 6 or 8 and may displace the ICR off the Maynooth line for use elsewhere.
The Phoenix Park tunnel service added 10-11 coaches to the morning/evening peak, but thats mostly entirely used up now. Not bad for a service Irish Rail said no one would use.
The original plan was to have DART services from Hazelhatch by now but the funding has never been released.
There are plans to order 41 more ICR coaches and up to 300 DART/hybrid coaches, but that depends on the NTA providing funding just to issue a tender let alone sign a contract.