I think it is additional capacity. The 2 Saab 2000s are currently operating IOM and Düsseldorf services and also have been covering some Angers and Bergerac rotations. Maintenance issues have been covered by other T3 S2000s, recently G-CIEC.
G-CIXW has generally been operating Rotterdam and Venice services since it started ops for BACF. Don't know if this will change as the winter schedules start.