We're ALL disappointed! :-(
Creating the Tips and Notes takes a lot of time, especially when writing explanations for the more complex topics that turn up as you work through the course. Since the course team consists entirely of volunteers who also have non-Duolingo lives and responsibilities, it is challenging to find the time to (a) conceptualize the content effectively and (b) figure out how to cram that content into (often insufficient) character limits.
But progress is slowly being made, so that's a good thing! :-)