mostly to prevent competition from patent-infringing clones manufactured in China.
FIFY
That's mental gymnastics. The fear is having to compete against cheaper products (possibly low quality, but possibly not). Even broken DRM is an excellent anti-competitive tool because no one can legally sell a competing product.
Publish a set of tests a device must pass, broadly, to be certified compliant.
Allow manufacturers test their devices, for a fee, and win a certificate, or know where they failed. Much like you can take a language exam (say, TOEFL).
IoT devices don't support public key infrastructure, e.g. something like GnuPG or the SSL certificates used by web browsers.
It's a very practical solution to have a shared secret between the device and a central server, and, at registration time, have the central server make a key for both the hub and the device.
Without some kind of key exchange, people could set off your alarm, turn on your lights, open your door...
Zigbee etc. tries to get around the whole thing by requiring that the pairing process is done from a 5cm or something distance.
Imho that is good enough but I don't know how far you could extend it with directional antennas etc.
That anyone can reclaim a device they hold in their hand is a feature.
So no, there will not be a published protocol.
Probably most toxic companies on earth? Yeah, I'm sure it will be a wonder of openness.
I know it has other issues, but particularly since ZWave2, the security model on ZWave far surpasses bluetooth or zigbee