I just realized that when not logged in and checking forum the first pinned topic is:
…it seems like a poor choice, if it was made by a choice - no?
I have unpinned - thanks for calling it out!
I had pinned that topic because it was a call to action. I believe that the sorting of pinned topics is simply based on which one has been updated more recently, there is no way to prioritize a pinned topic over others.
I’m not arguing about the unpinning, just explaining why it was pinned. 
You are welcome.
Understandable. This is one of the limitations of Discord UI.
Quick fix would be to have category Calls for Actions (or similar)
and have it show only to logged in users who already made
first use of Forum by discussing or other actions - no?
How about having a tag for “calls for action” that we can point to? Though I don’t think you can pin tags, so it wouldn’t really solve for the problem… (I’m offering this alternative proposal because the categories are based on the 10 Movement Strategy recommendations, and calls for actions should probably be categorized accordingly, to make sure it is pertinent to the Forum?)
I do not have clear overview of tagging and taxonomies options or decisions made until now, but I would not block a feature for single use (that is just reductive UI/UX wise)…
Maybe someone else can respond to this?
I think the current functionality is fine. We can expect Forum's basic instructions to keep being pinned forever, and then we can have, 0, 1 or 2 more temporary topics pinned based on current events.
Discourse allows setting the time frame a topic should be pinned. We can pin a topic for a selected time frame and forget about it.