Brave, considering RYR chased them out of ORK and SNN with extreme prejudice last time they served Ireland. RYR did the same to Wizz also.
I'd describe it as stupid rather than brave, to be honest. The problem is that everyone who was at easyJet last time they went onto Ryanair's home turf is no longer with the company, and so the trigger for someone to say "look, this is a really bad idea - remember what happened last time?" simply doesn't arise. It will provoke a disproportionate reaction whatever the route is (my guess is that it's LIS-DUB as easyJet keep trying to find ways of using their Lisbon slot horde) and it really is a crazy thing to do. The more you see of easyJet's network management, the more obvious it becomes as to why the airline is under-performing so badly.