I think the explanation next to the "allow uncategorized topics" should be a little more descriptive, explaining that staff are immune to this limitation.
Staff are immune to tons of limitations so I don't feel this needs to be specially explained. Try replying to a closed topic for example.. so all close messages should say
This topic is closed. Except for staff!
I think a just-in-time warning for staff members when they're creating an uncategorized thread would be sufficient and unobstructive.
So let's merge into this: