KLM do line engineering at most of their UK destinations, with MME being an exception up to now - at a guess the guys based at Newcastle have been asked to cover MME as well if it isn't a separate unit.
I'd be surprised if it is an actual shift of base from NCL, purely on the number of flights per day at NCL (would expect the engineers would cover all the short haul types, so don't think that would come into it)