Old URL feature gone? (ignore_spoiler_for=)

Before the filter thing happened that used to be a thing that would unspoiler one specific tag for a page. Now it doesn’t do anything, but it’s still automatically added to URLs on tag search pages. Like, if you go to the tag listing, hit questionable and then go to page 2 you’ll still see it show up in the address bar, but it won’t have any effect.
 
Is the removal of that intentional or just a side effect of something? Is the tag search supposed to still automatically add that text upon page navigation?
 
Wasn’t sure where to look for this kind of thing already being answered, so if it was, my bad.

This is a bug, we are working on it.