After clearing a pin from a topic, I think that a greyed-out “cleared pin” icon should be shown - to visually show that although it’s not pinned for you, it’s still pinned globally, and offer the chance to re-pin it.
The icon should also show up in the topic list. In some communities, pinned topics still get action, and currently if you cleared the pin, it would show up in latest with no special indication that it is still pinned.
This would also solve the moderator confusion when they clear a pin that I’ve seen some discussion about.
I made a quick mockup in paint:
As you can see, I’m not that great at visual design, and merely okay at writing words with a touchscreen
This feels to me like a pretty clean solution to one of the ‘stickler’ problems that’s been hanging around.