Upgrade to 9.3P1 fails on 9.2 AFF cluster

A short while ago my colleague noticed that 9.3P1 went GA, after upgrading and testing our Dev Sims we decided to upgrade one of our current 9.2 clusters of a pair of AFF8080's


Upgrading via the Managemnt GUI seem to be going fine, we have successfully done this several times, the process is automated and usually works roughly as follows


Failover to Node 1, upgrade Node 2, and then giveback.  Failover to Node 2, upgrade Node 1 and giveback.


Node 1 failed to update and was rejected during giveback as its WAFL and RAID versions were wrong, Then after trying to resolve the issue the WAFL and RAID versions were updated and the node then rejected them and would shutdown to "LOADER" prompt on boot.


The resolution was quite simple but required NetApp Engineers help and involves netbooting the node to 9.3P1 and manually upgrading.


Strangely 9.3P1 no longer appears to be GA