Orbit did a big HomeKit press announcement during CES (many tech blogs wrote stories based on it), then they appear to have pulled it all back (minus the citing you noted, which looks like something someone missed). Why would they do that, unless Apple asked them to?
The fact that some of their products are shipping with HomeKit setup codes in them, despite their product not even being certified yet, is something I’ve seen no other company do. Doesn’t sound like something Apple would knowingly approve them to do it.
My guess is that Apple is delaying things unexpectedly, and Orbit based their launch around the thought that HomeKit would be ready by then… and it wasn’t.
Rachio’s logo was on Apple’s HomeKit partner list last year at WWDC. That’s all I needed to see.