some of the code is “older” and doesn’t follow the latest definitions that are defined at [1] - I assume you didn’t read it already?
There is even a code generator (React Component Generator) that follow that, the fact that its not known to developers is probably leading to the important point that enough communication is probably not happening…I know the UI team does try to send a newsletter( e.g. Foreman UX newsletter - January 2019, but maybe that’s not often enough…)