Not a NERC Upgrade
This will be a NAS upgrade if anything and shouldn't have affected you much.
The next two NERC upgrades will be:
1) Night of 6/7th Nov. New functionality to make the ATCO's life a bit easier, including pilot Requested Flight Levels and Auto-Accept not sorted until the P hits the tidy button.
2) Night of 27/28th Nov. Change to software due to Sector 7 (Irish Sea) being removed from LACC control.
We have learnt a lot of lessons on LACC shutdowns and the process is now quite mature, so you should find that the previous quite heavy restrictions are a little eased.