AA and EI serve PHL-DUB. AA on a 787 and EI a 321Neo (with 16 lie flats up front). They are both in the OneWorld alliance so they feed each other nicely on either end with connections. F9 would have a difficult time siphoning off some of that traffic. PHL-SNN or Cork could work as long as AA doesn't go back into those cities. If F9 is going to do Europe from PHL, they could hit some of the other cities AA abandoned like EDI, MAN, TXL and they could also serve the secondary airoprts in Paris (Orly) and London (Stanstead or Gatwick). But with a 321, they really have to rely on passenger revenue whereas the legacies can load up the widebodies with cargo that is a cash cow. I'm not sure how much weight is left to allow for cargo revenue on a 321 if they also need to load it up with fuel and pax.