I highly doubt that we will see Microsoft Flight Simulator 2020 ported to Linux any time soon. A Linux port would require one of two things to happen:
Either Microsoft would need to port DirectX 12 to Linux or Asobo would need to port Flight Sim 2020 to the Vulkan graphics API. Seeing as Asobo has just spent the last year porting the sim from DirectX 11 to DirectX 12 I highly doubt a Vulkan port is also in the pipeline. I also don’t see Microsoft porting any version of DirectX to Linux as having exclusive ownership of the most dominant and widely used graphics API in PC gaming gives them a huge advantage when it comes to convincing/forcing people to use their platform. There is always progress being made on the translation layers like Valve’s Proton software and Wine but the unfortunate fact of the matter is that running DirectX games using one of those translation layers is still a total dumpster fire compared to native Windows environments. Gaming is basically the last bastion of defense for Windows as a home operating system and if DirectX becomes available for Linux then there will be absolutely no reason for anyone to use Windows on their personal computers ever again.