What's the reasoning behind this change?
Players can enter the Kharid-et praetorium without a Ring of Visibility.
The original intention when designing the skill was for the core excavation spots (those with artefacts) to be mostly locked behind just Archaeology requirements. The ring of visibility requirement was a slight oversight.
We were happy to place outside requirements on material caches and mysteries, and we plan for future additions to the skill to also include outside requirements.