Hi Sebflyer,
Our industry is notoriously cyclic, You'd be a brave person to forecast that far ahead!
The estimates for numbers of pilots required vary a lot throughout the year, and within BA there are various pools of people they call upon depending on the present requirement (Direct Entry (DEP)/Ex military/cadets etc), so it's even harder to predict.
All you can do is put yourself in the best position to be successful when the opportunity arises (look at the entry requirements/subjects/grades) . I applied at 18 to the old cadet scheme (and failed), went to uni and upon graduating BA weren't recruiting, so applied elsewhere and was lucky to get sponsored, finally ending up in BA as a DEP a few years later.
I wish you and all others applying the best of luck.