I doubt that it's a misunderstanding. Google should have anticipated some backlash and likely weighed the risk versus the long term revenue benefit. This is a power-play to cripple access by competitive products.
My only investment in nest has been 5 nest protects. But I was looking at a couple of nest hello devices. And while I'm certainly not going to run out to replace the protects, I won't be buying a nest hello or any other nest product until there's more info about how this is all going to pan out.