We do not officially support Linux and we cannot commit to having support for launch. We are still working on Official Linux Proton compatibility. This official stance has not changed since pre-release. We admit there was a mistake in communication by our CM which was unfortunetly screenshotted in our Discord and then posted on the linux Reddit, when the official stance has always been 'we are working on proton compatibility'.
You usually develop for an engine. It’s the ring 0 spyware they use for user tracking that only runs on Windows.