hi and welcome to OSM.

Please see https://wiki.openstreetmap.org/wiki/Australian_Tagging_Guidelines/Cycling_and_Foot_Paths#Legal_Access

OSM can contain data for sanctioned, informal, and closed/illegally constructed paths and our guidelines page explains the reasoning and what tags can be used to communicate the exact situation on the ground to OSM data consumers.

Essentially if there is some physical evidence on the ground, then it can be mapped in OSM. If there are track closure sign, or other substantiated sources indicating no access we can mark that with access=no, and possibly mark the track as abandoned or disused if formally closed off for rehabilitation.

Further you can use informal=yes to indicate it's not a formal track.