Late May would be wishful thinking, but perhaps a July release is more likely. Verizon still has to test the phone and we know that can take months and months.
If its entirely new hardware, then yes, that would take some time to test. However, if it is in fact a revision, as they say. Obviously they completed a good bit of testing in order to determine that a revision was necessary. At the very least we know the LTE radio has been changed, hopefully there's 1gig of RAM, and we don't know what other changes there are. But I would assume that testing would mainly involve confirming that the issues have been fixed, as well as proving that everything else works as before, and that the changes have not caused any more problems. Then complete whatever testing could not be completed due to the device's failure to be approved, and that's it.
I realize that will still take time, however I don't think it will be nearly as much as a brand new device. Considering how much VZW and Moto both have riding on this device, and how eager they both must be to get it to market after such a delay, I'm thinking they'll want to get this thing finalized as quickly as possible.