Quoted By:
Most likely they couldn't settle on a way to make it work that wouldn't be kind of weird. I think Fitbit's monitoring your sleep, you have to physically wear your watch to bed which most people wouldn't do.
Sleep looked like it had some sort of device that sits on the bed but i dunno how that would even work besides monitoring you tossing and turning. I think there was some kind of Snorlax plush that had Sleep branding but that was changed to regular Jazwares stuff when it went to retail.
I'd say its probably dead or they're trying to figure out some way to monetize it or loop it into Go proper.