Well I don’t have this assistance option available, the only options related to ATC under Assistances are : AI Radio coms, and ATC enfore FPL. Both are unchecked. Could the setting you mention be somewhere else ?
I never interract with ATC and yet as soon as I start a flight directly from the RWY, I can read in the ATC window that the AI has already made all the communications from parking stand to runway, so when loading the aircraft on the runway, the AI makes the “Ready for straight out departure” call. If I start the flight cold and dark and don’t interract with ATC, I don’t have this problem indeed.