Assume hidden keywords to be available by default #16747

Description:

fixes #16742

Review

• [ ] Functional review done
• [ ] Usability review done (is anything maybe unclear or think about anything that would cause people to reach out to support)
• [ ] Security review done see checklist
• [ ] Code review done
• [ ] Tests were added if useful/possible
• [ ] Reviewed for breaking changes
• [ ] Developer changelog updated if needed
• [ ] Documentation added if needed
• [ ] Existing documentation updated if needed

Would it be a good idea to add a visit w/ a hiddenkeyword referrer to a system test as well as the unit test used?

@diosmosis added simple system test