From the blog post:
TL;DR: We have joined the Z-Wave Alliance, thanks to revenue from Home Assistant Cloud subscribers, and will start the certification process for Z-Wave JS.
As a z-wave user myself, I am pleased by this. I was apprehensive about Z-Wave JS at first, but its been super reliable and stable for me.
The first few devices I bought were z-wave. £40 for the radio, and £40-ish for the devices.
I would not recommend starting that way! I nearly balked at the cost of the radio.
However, it did work out, as my main heating control is z-wave, and stability in that is really important.