Seeing this pains me, especially considering Id Software's history with Linux. Prior to being bought by Bethesda, most of Id's games had official native Linux ports. Even Doom 3 had a native Linux port, it doesn't seem to work anymore but there are source ports like Dhewm3 available for it.
This is what happens when bean counters make the decisions. Linux is only 4% of market share so I am sure the cost of supporting Linux users was not worth it.
It wouldn't astonish me if this were a semi-deliberate act by microsoft. While they're trying very hard to expand to every platform, non-windows pcs seem to be the exception. Linux and OSX have the game gamepass support as your phone.