And see, I think just the opposite. I think Morrison wanted to do a story about a multiverse, and DC let him do it (because he's, you know, Grant Morrison) but had no intention of really doing anything with it beyond that.
Worth noting that Morrison started on Multiversity a long time before the new52 relaunch. So they might have even had more of an intention to do something with it at that time, but it took so long to get it produced that other plans changed in the mean time.
Morrison is a very creative person, so naturally he's going to lay foundation for other stories in the versions of his Earths. Although, to my eyes, too many of the Earths were pastiches of other publishing companies' characters, rather than actual original concepts.