Split of Issue MDL-65332.

The recently accessed courses block appears to only track access to courses that the user is enrolled in and that are set to visible. However, it should also track access to hidden courses that the user has accessed.

Without taking care of the admin case (see MDL-65332), there is less risk of missing performance/clustering standards.

Of course, we run the risk of showing students (or people whose access rights have been revoked) courses to which they no longer have access.
But given the benefits (lecturers complaining that "the recently accessed courses block does not work during term preparation when courses are still hidden"), I think this is a risk we can mitigate.