A very quick check on the schedule shows the aircraft will do LCY-AMS-LCY instead. Presumably BE have decided that one round trip to/from EXE-LCY will be enough on a winter Sunday, and the AMS rounder offers more revenue potential.
Such minor tweaks are generally not announced to the World at large, but anyone who has booked a seat on the consolidated flight will doubtless get an e-mail.