I think I may have found a bug but happy to be told it is by design if that is the case
I needed to split a topic into two as the content had wandered from the original subject.
I created a new topic and set it as unlisted.
I then selected the posts from the original topic I wanted to move to an “existing topic”, but when I typed in the title, no results were found.
I spotted the mention of entering an ID, so I entered that and sure enough the topic was found and I could move the posts.
This leads me to believe that the search for existing topics filters out those that are unlisted, where-as by ID does not. As I said this may be by design, but I can’t think of why - in this context - it would be?
I would say it is sort of a feature request. Shunting stuff to a hidden topic (or restricted category) is a recipe for mistakes.
IF
hidden topics were always at the end of the list
and, we were super clear in the UI that a hidden topic is hidden
and, added a confirm … “Are you sure you want to move these topics to a hidden topic?” (or another case “Are you sure you want to move these public posts to a restricted category?”)
The reason for the choice of unlisted was merely temporary. It was so that I could copy and paste the relevant chunks of text from the original posters topic into a new topic, change ownership of it to them, then move the relevant posts from the original topic to this one - then - editing the original one so that it made sense again and was tidy. At the end of the process the topic was set to listed again. The use of unlisted was merely to keep all of the to-and-fro from the public eye whilst it was happening.
I like all of the bullet point items you raise, especially the third one, the warning etc.
p.s. thanks for the correction, I wasn’t trying to assume it was a bug per-se, I just couldn’t think why I would be able to move posts to an unlisted topic via ID but not title.