Mine did the exact same thing went from 3500, down to 300 miles and then straight to service now, all I had done was a short trip 15 miles, had given it some beans once it had warmed up but nothing like WOT or redline, so was really shocked when it had popped up service now from 3000.
Anyway rant over, if your on long life then its supposed to be based on an oil sensor which will be monitoring the oil quality. but it also has parameters of maximum distance, and time.