The pilots applying under the managed path option have a very long lead time before they can actually start their employment with BA. Unlike DEP who generally have a 1-3 months notice period, the armed forces have one which could be anything up to a year. Hence why managed path is probably open since successful candidates will only slot in somewhere over the next twelve months (on the line for summer 2016). While at the same time the rated DEP pilots are fast tracked because of the current requirement for Airbus pilots.