You can't hide certain pages, but you can follow specific pages, having only those pages appear in Special:Watchlist. Instead of a blacklist, it's a whitelist.
Hope this helps!
Okay, I understand.
But, i'm confused how other wikis get pages to hide from the feed. like spongebob wiki hides request pages.
I see a request page on Special:WikiActivity and on Special:RecentChanges. The latter link allows you to filter out request by unchecking the "ESB" box (if that's where the request pages reside).
Would this feed you're referring to be different to the ones I linked? If so, can you provide a screenshot or link directly showing the problem?
I see. No worries, this is normal. The reason 'request' pages don't appear on that list is because they are on a Project namespace. The feed you screenshotted only lists edits done on Mainspace pages, that is, without a prepend before a page title (though I haven't explicitly tested this and can be wrong).
The project namespace on the Spongebob Wiki is called "ESB". If you look at my screenshot, you can see the 'request for chat moderator' comes after 'ESB:', meaning the request is on the project namespace. Meanwhile, "Gary's Got Legs" does not have ESB as a prepended element, making it a mainspace page.
Thus, the request for chat moderator page does not appear in the activity feed in your screenshot. This appears to be normal, as I have tested this theory on a sandbox wiki of mine, and editing my project namespaces don't have such edits appear on the siderail feed.
Would this address your issue? Did you see a project namespace page appear in the feed before on another wiki?
That makes sense. Unless a technically proficient user can join, I would recommend contacting Fandom Staff about this issue and also checking out the Dev Wiki for potential solutions (their Discord server can help guide you; the official Fandom/Gamepedia Discord can as well).
All the best!