They're basically talking about the fact that ANAD isn't a full reboot, and as a result, is leaving everything in a really tenuous state of flux. Like, yeah, the multiverse died and was reborn... but the new multiverse kept the continuity of the old one and a shitton of people from the previous multiverse carried over. It's still the same universe, but it's not.
Traditionally, Galactus' "role" was to facilitate the change from Universe-7 to Universe-8. He would be the devourer of 7 so he could give back the energies, cause the big bang for 8, and then become a new entity there. But that didn't happen properly because of Secret Wars.
So some of the abstracts are looking at it as "since continuity wasn't fully rebooted, that means the universe wasn't rebooted properly and the cycle of death and rebirth has to be completed." Those abstracts want to bring the status quo back to how it was before Secret Wars, so stuff like Galactus being the Lifebringer flies in the face of that. Other abstracts see the change from 7 to 8 as incomplete, so they seek to have the universe be destroyed and reborn properly as opposed to the weird semi-reboot clusterfuck that ANAD is. Full reboot.
In the end though, the whole argument is moot, because they're arguing about whether status quo should be reset to how it was or if the book should be closed on the Marvel Universe with a definitive end, when in fact, the true destination is in fact the journey from status quo to conclusion itself. In other words, should the rock (the universe) be at the bottom of the mountain (the start, the status quo, where the very nature of cape comics will always pull the narrative back down to) or should it be at the top of the mountain (the destination, the end of the narrative).