Given the quantity of doses stored, it seems likely AZ has been having them make doses that (likely) pass their own QA for some time so they should be in shape

Given the quantity of doses stored, it seems likely AZ has been having them make doses that (likely) pass their own QA for some time so they should be in shape to receive approval for a comparable amount of time. To me one likely explanation for this is that AZ was holding off on applying to the EU in the hope that they could make these doses "in secret" and sell them outside the EU. Another, more mundane one, is that their back office is just a total shitshow with so much panic going on that somebody just didn't file it.