Wikimedia Bugzilla is closed!

Created attachment 12025 [details]
Screenshot showing Special:NovaProject when no projects are selected and filter is hidden.

This much seems uncontroversial: when no projects are selected, the project filter should be visible. Otherwise the page is blank. (See attachment.)

I think there's a case to be made for going further and removing the toggle functionality for the filter interface altogether. I expect the ability to hide it  is only really useful if you're managing lots of projects, which is true only for a handful of administrators and not the majority of users.

Last but not least: there is a FOUC (flash of unstyled content) which causes the filter to be shown briefly before it is hidden. I can submit a patch for fixing that if you like, but consider first my suggestion to remove the toggle functionality altogether.