You do know that Unreal 5 has a native Linux build and source available from Git you can compile and develop for already right?Sweeney will once again just hang back, let Valve and others take all the risk, make all the investment, do all the heavy machinework boring a tunnel through the linux gaming mountain. And then he'll show up and declare "Valve's linux gaming monopoly out of hand" and announce EGS for Linux here to save us all, as the desperation giveaways commence.
https://docs.unrealengine.com/5.2/en-US/linux-development-quickstart-for-unreal-engine