They are going to add Linux support the game is in alpha.
That’s not day 1. Why do I need to say it over and over again? It’s not like I spelled it out already: CS2 had a Windows-only pre-release and the Linux port was only added to the formal release, resulting in the Linux port being very buggy to this day! Their own platform needs to be the top tier development target from day 1. How is that difficult to understand?