Abi and Brooks are very...practical people, I think that's the best way to describe them. I don't think they particularly want to get to the bottom of this; they really want to keep their heads down and wait until everything blows over. Given the chance, I doubt either of them would use their powers at all unless they're in a life-threatening situation. The plan was always to get out, disappear for a few years until their names are no longer on the news, then regroup and rebuild. Wandering headlong into trouble isn't on their to-do list, and so far the group's been nothing but trouble. In the collab, Abi's going to spin the situation so it's less "These people want to kill us" and more "if we play our cards right, we'll have free food, free lodging and a team of superpowered bodyguards, and we have nowhere else to run to" but even that's only going to keep them around until whatever fight AcerRo has planned comes up.
The most annoying part is the inability to use sentimental/emotional excuses to keep them around. I doubt Brooks is going to make friends at all, and Abi may be warm and friendly on the outside but she's also 100% ready to bail if things go south. They don't give a shit about the group, only each other. There needs to be an incentive for them to stay. I only know of one idea, and I want to avoid that unless I really have to use it, and that'd be blackmail; whoever Julian Guiderone is he'd probably know who Abi and Brooks really are. One quick phonecall telling them to stay put or face the cops and they'd co-operate. But...it's just a really clunky, forced way of doing things and brings in an NPC who seems far too important to delve into such petty matters.