The content of Page Properties macro is available from the search even if it's hidden (with Hidden property) on the page if the user has View permissions on space or "Read Only" restriction for the page.
The issue is reproducible with anonymous access as well.
- Create space
- Assign View permission on this space to one of the groups
- Create a page in that space and add Page Properties macro with hidden attribute
- Search for the word used as an attribute or as as value in Page Properties macro
The text from hidden Page Properties macro is available in search only for the users with Edit permissions
The hidden text is available in search results for all users with View permissions
No workaround currently avaialble.