I managed to update it to normative language with the reference as a note. This makes sense I think, and lets me reference the wpt tests for this web-platform-tests/wpt#34912.

Thanks @aboba, when I tried to incorporate that, I found it similar to the paragraph on active/inactive directly above, so I've tried to move it there instead. I figured out how to do an informative reference from a normative section ([[?foo]]) so I was able to remove the note. PTAL.