I tried it on my Nokia 5 and it seems good. Hope Nokia will improve it so that we have many more customizable options
The Z Launcher was developed by Nokia, not HMD. So they'd have to get it from Nokia first. At any rate, I'm not sure how popular it would be with actual consumers. I've always seen the Z Launcher more as a statement that Nokia wasn't going anywhere after the attack on their D&S division, rather than an actual project with consumer appeal.
You can download it from the Play store or direct from zlauncher.com. There's no reason you can't use it.
I also installed it in my nokia 8 2017 running android oreo 8.1 and works without problems...exactly the same as in my nokia n1 tablet. I can confirm that despite z launcher still remains in beta...it works with the latest OS from google