I can confirm that this is correct. More info here: https://bathurstestate.co.uk/cirencester-park/passes-tickets/
Entrances at Cecily Hill, Windsor Walk, Barton Lane, and the Caravan Club will be gated. 
As far as I can tell, other access points may not be gated so this will need to be surveyed and mapped accordingly. Examples of possibly ungated access points include at the public bridleway from Stratton, at Sapperton, and from the roads running alongside Oakley Wood. There could also be others that I am not aware of.