I don't know if this would be a consolidation of a few of their existing OS's or an entirely new one, but in general I'm concerned with the amount of OS's they have to manage. Even more so with rumored AR/VR and car products presumably on the horizon. I personally don't think they do as well as they need to be. Apple's always primarily been a hardware company with the software supplementing. But with Services increasingly being a larger focus and a significant contributor to their bottom line, I think it leaves even less room for sloppy software management. Something I think they've been getting worse at as they add more (watchOS, iPadOS, tvOS, etc.). I think it's still passable and not a deal breaker, but I guess I'm just concerned based on what at least I observe to be a downward trend with quality and consistancy.
That being said, I would LOVE Apple to be more serious and successful with home automation. I want them to prove me wrong. I'm just concerned is all.