I see that CAP493's predictions were proved correct and that there was no night closures during the early hours of yesterday (Sunday) and today.
I've just checked the NATS website and the original NOTAM is still there and is now proven to be incorrect. The additional inaccuracies relating to hours of closing once local time = UTC also remain uncorrected.
Who writes the NOTAMS for Luton - ATC or the airport authority?