For some reason, I don’t see your reply in the discussion group.
Below, it sounds like you’re conflating “features as a part of the release” (what’s checked into the code) vs. “features that are listed on ChromeStatus as being part of the release” (documentation). Unfortunately, these aren’t the same things, and it’s certainly the case that features can go into Canary/Dev without an up-to-date ChromeStatus entry.
I believe Chrome’s tech writers push engineers to ensure that ChromeStatus is up-to-date at some point during the development cycle, but I believe this might happen around when Beta is forked.
-Eric