If they were to recruit for CSA's again it will most likely be for Night Tube if anything and that won't be till next year. There's quite a large influx of CSA's atm and they'll be waiting for movement/promotionals before recruiting for full time CSA's.
There have been quite a few internal campaigns mind you so quite a few CSA's across the combine are likely to be promoted so if anything they may need to replenish their waiting lists next year to backfill any vacant vacancies.
If that were to be the case, it won't be till next year anyway. As always just keep checking the careers site.