We have now had confirmation that the bus service will continue during the closure of Bicester Road (from 28 March).
The buses will enter Launton via Blackthorn Road, then turn right into Station Road, setting down opposite the bus shelter, then stopping and turning round at the bus stop in Blenheim Drive (as the S5 used to do). The bus will then stop at the bus shelter and exit Launton via Blackthorn Road.
So, at the moment only these two stops will be served, but there may be the possibility of adding a temporary stop on Blackthorn Road.