Although allocating everything in one place helps when it comes to sifting through the add-on section, there eventually will be a point in time when the UI topic will become so bogged down that it will take forever to find anything in it. If you place something outside of the topic, then it will receive its share of attention for as long as people want it to and then will eventually die and those who aren't interested in it won't have to see it anymore, what's so difficult about that.
As long as the creator groups all of his/her releases into a single topic, I see no problem with what he/she is doing.