I haven't seen anything else about this since the original announcement and now that iOS13 is out, I was hoping we'd hear at least a little more about it now. Am I just missing more details, or does it not really exist?
Not yet. Sometime this fall, supposedly. Maybe 13.2?
My unfounded theory: further news tied to updated Apple TV in Oct since some of the video processing is supposed to be passed off to the hub, and current ATVs are pretty weak in processing power compared to current chips.
Edit: I was having a hard time finding it on apple.com. Found a reference on the MacOS Catalina page (!):
So hopefully something this month. I'm really excited to learn more about that service. I use nest right now for security cameras as I like the always recording option, but to have encryption done locally is very desirable as well.