Clearly this means they don't intend Apple Watch to pick up sleep tracking though. My Fitbit needs to last a few days because there's only a couple chances I really take it off to charge.
I think it didn’t make the cut at the last minute. The code has been in the betas for a while and there have been a bunch of “rumor” articles about it. Usually when there are that many rumors they’ve been seeded by Apple PR.