It seems that’s pretty much what I wanted, i.e. the topic should be locked to a custom “team” group + specific user. If I was to add another member to the “team” group, then that member should be able to see the previous messages exchanged before he was added to the “team” group.
I like Discourse very much so far! … and I gotta say, I love the proper programming concepts it’s based on (as opposed to the mess that Wordpress is and how my blood used to boil whenever I had to deal with its API). In less than 20 minutes with the rails interface for Discourse yesterday I was able to figure out and do quite a few things by simple command completion + peeking at /master/app/models (I regard that as a measure of how well code is written). Well done to the Discourse devs!
// and that’s coming from someone who dislikes ruby/rails