User blog comment:ADour/ALL-NEW, ALL-DIFFERENT MARVEL first look!/@comment-3216868-20150606123032/@comment-1243861-20150622103352

It's the tried and tested technique DC have been using for years. My guess is that once Secret Wars is concluded the multiverse will be rebuilt and the main universes (In publication) will once more exist though radically altered (Means they can bring out some new origin stories to update the timeline and shift it forwards again). The ones that are no longer in publication or are the what-if storylines with characters we all love but can't see because obviously they aren't a part of any running publications and are what-if characters or throwaway story universes! I think those will be wiped out and the characters from those worlds will be shifted to reside on whichever reality they are thrown into, that's all dependant on whether the mainstream and the ultimate universe (The Two most well known realities) are separated once more or if they are merged. Judging from the promo It looks like it will be merged. Either that or all of the Ultimate characters are gone while Miles is the only one to survive and joins earth 616. Another possibility is that they get rid of the multiverse all together and merge it into one universe after battleworld. That would cause a whole host of problems regarding refugees from other universes.