Duplicated from my comment on https://github.com/splitbrain/dokuwiki/pull/376
as that pull request has already been closed:
After applying https://github.com/splitbrain/dokuwiki/pull/376
(which was two months ago) it's not possible anymore for plugins to add feed items for hidden pages to the feed unless they replace/copy the item builder code. For example I could imagine that it would make sense to write a plugin for listing all revisions of a single page that works with the standard feed item adding code that should also provide feeds for hidden pages.
I think the filter if pages are hidden should be in the same place where the check if the page is ACL-protected is. Both the recent changes list as well as the fulltext search are already filtered to only contain visible pages, I think the only mode that didn't have a filter is the namespace list mode. If we check again if the page is hidden, why don't we have an additional ACL check, too? In my opinion the check if the page is visible doesn't belong at that place in the code but in the code that generates the list of pages that shall be listed in the RSS feed.
A possible fix is in https://github.com/splitbrain/dokuwiki/pull/464