Indeed we generally seek to encourage more sharing here on Discourse. However with the size and diversity of the community we can’t put everything on one channel. There are a lot of people that care only about a subset of the development.
I think that you’ll find that we do try to make sure to raise any medium to large scale changes here in the forums. We certainly do that with anything that is distribution wide.
Often topics of larger interest are raised here with links to more in depth discussions on issue trackers. Discussions on the issue trackers are much more efficient where they can interact with the code and be done line by line. This can also allow the whole community to listen to the announcements and notices without being required to listen to the full details of the discussions, but they can opt into listening and or participating.
Part of why you see more traffic on ROS2 is that it’s being actively developed and changing rapidly. A lot of the ROS ecosystem has been developed and matured and is much more stable. There is still active development but usually it’s incremental in nature, and we work hard to make sure that everything is backwards compatible so that changes are not disruptive. If there are changes that might be disruptive those are often escalated to an announcement and request for feedback.
For questions we highly recommend using https://answers.ros.org/questions/ It is a place where the community can find answers. A well asked and properly tagged question there can usually get a good answer. This includes questions about past design decisions too.
As a way to gather interest in a project I suggest posting in the Projects category with an update on your project. It’s a good place to gain visibility and others who are also interested can look into your project to volunteer or help out. And we also encourage announcements of new package releases on the General channel too.