..They can only be on the route 'commercially' as from 1st November. A one flight a day flight is not the basis of the PSO and if the Government get another airline to run the PSO - he won't be allowed to run his 1 x flight a day. He will not be allowed to cherry pick to screw up the PSO.
EU Law won't allow PSO on Commercial routes.
I doubt there is a huge worry in Irish Govt regarding PSO routes given the state of their finances.