I'd expect BA to run the FPP for the next 2-3 years recruiting around 300-400 people in total over its duration. The current batch in training are expected to start joining in Aug/Sept depending on flight ops not having a pilot surplus and available training slots on the Airbus. There's lots of space in the 737 sims, but the fleet is now being wound down in favour of the Airbus.
If I were a betting man, I'd say next years recruitment would be at about the same time as the last one.