It's definitely more popular this time, since debuffing is out the window this event.
I personally fall on the healing side of the table, as stalling can create miracles across any game. But you also need two things to make it work; the bulk and sustain; can't heal if you die in one hit.
That was one reason my Union didn't completely invest in recovery for the 1st Union Event; lots of us didn't have a weapon/eidolon grid tanky enough at the time to capitalize on it (debuffing was also huge for that event). So if your Union isn't tanky enough to handle it, offense is the best defense (and is a default setting that should work with everyone).