In a bizarre move by Google, they are closing out their "Works with Nest" program effective at the end of August and have decided that only google products can control google products. So, no more interoperability through open projects like Home Assistant or OpenHAB and possibly no interoperability with things like the Echo or Harmony remotes.
I can't imagine that Google shutting out their competitors isn't going to force their competitors to say "ok, fine, our products work everywhere but in the google ecosystem." In the end either Google strikes a deal with the bigger manufacturers to continue with some kind of special API or they'll suffer the backlash of manufacturers. This seems to me as a very arrogant move. It's like they don't know that Amazon still holds the market on voice assistants. Do you really want to piss off Amazon right now?
https://www.tomsguide.com/us/google-works-with-nest,news-30053.html