Tried it just a few minutes ago. Again, it did not work for me. I can log in into my mi account and select to give the permissions, but in Google Assistant setup it shows no devices.
(Lineage OS 14.1 (Android 7.1.2.) on Samsung Galaxy Note 3)
But as I said: it's ok for me, I use my Echo Dot to control my Yeelight. Works like a charm.
No need for me to follow this Google issue any further.
I would have to activate the screen of my smartphone, then ask "ok google, turn on.."
Now i just have to say "Alexa, turn on..", without having my smartphone at hand. Much easier and more convenient to handle.