Some systems already have that. Replaced a switch yesterday and re-arranged some things on my network board and got a HomeKit notification that some things were offline and when it came back. Knowing when something goes offline isn’t as useful as keeping things up though. With something like a hardwired camera/NVR, even if your ISP service is interrupted the cameras can still record, and you can put a UPS there to keep things going, even if the rest of the network is down.
Yep, lots of things like cars, home appliances, home theatre components, etc. get regular, if not yearly, updates even when some of those things have a 10+ year lifecycle for the average consumer. It’s not like Apple stops supporting devices after a couple years. With things like the Apple TV that aren’t updated as often I end up putting off buying something that I want because, like you said, it might already be 2+ years old and I wouldn’t want to feel behind when the new one comes out less than a year later. I’d rather see smaller updates more often so there’s always something recent when I’m looking to buy.