Unfortunately they’ve not said if they intend to do this so I’m going to assume for now its still no.
I can totally see why there are people who want a Linux client but I’m not so sure Blizzard wants another platform to support for WoW because there would be potential for Linux specific issues.
You should try different DirectX settings within WoW itself, on my old PC I found the DirectX 11 setting within the wow Client to work smoother than 12 when running it through Linux.
I would also download the up to date Battlenet launcher from the website and direct Lutris to that when installing because it would spend some time updating the older one suggested by Lutris itself which took longer.