Support for the `user` context in the Client Credentials

Hi, I previously read that the `user` context was not supported in the Client Credentials-based authentication. However, the current documentation seems to indicate that it is now supported.

My question is whether this functionality has also been made available in older versions of ServiceNow for customers who choose not to upgrade or prefer to stick with an older version. If not, is the `guest` user specification used in those previous versions?