I can't see a great reason for AB coming into DUB, when their mainly US-focused hub is in the already well-serviced DUS and it offers no discernible advantage over travelling with EI. Besides which, with AB already being a member of Oneworld, and EI seeking to rejoin it, there's no real need for the two to compete. As for Berlin itself, there'd be precious little point in chasing the same market as FR, as EI would be the only carrier to offer meaningful connections on one of two ends.
Lisbon is one of the more genuinely interesting hubs, and now that TAP are pensioning off F100's in favour of E190's, there may be room for them in DUB. The route would have a scaled down dynamics of the DUB - AMS route, insofar as FR would concern itself with O&D, EI would concern itself with connecting people between Europe and N. America, and TP would well-placed to concern itself with connecting the Irish to S. America and some points in Africa.