The creation of the MAA raised the airworthiness bar leaving Airseeker unable to meet the new criteria for service entry.
The bar hasn't been raised. It is just that PTs and ACAS are now required to clear it, whereas under previous regimes they were allowed to make false declarations that they had cleared it, knowing that they had not. See Chinook ZD576, Tornado ZG710, Nimrod XV230, Hawk XX177 etc etc. If Airseeker can't clear the bar, then that would be because the PT hasn't set its sights high enough in the first place. Same as Nimrod MRA4.
I agree with the sentient expressed above -re MAA and the boxes of evidence. They should have been working alongside the PT for the last 4 years to ensure that nothing came as a surprise when the recommendations were drafted for ACAS. However, the MAA DG's comments imply this hasn't happened. Their jobs are to avoid the avoidable, and manage the unavoidable. The boxes he speaks of should be the latter.
As Wensleydale said, in so many words, it is unlikely the MoD has sufficient people of junior enough grade to do the work. All this should be basic stuff to the most junior CS in DE&S. Few, if any, at this grade work in the MAA, which says it all.