Which means there's virtually no value keeping the _CanFindParentLink class, just merge it into InvisibleModelAdmin.
These docs suggest the original intent of "InvisibleModelAdmin" was to NOT show the child model in the admin interface listing.

Which would imply that having a flag like "invisible_in_admin" on such a class is just silly, and a sign that the class may have too many responsibilities and should be broken down into separate mixins if such responsibilities are actually required.