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'.
Not more then you have available with proton. And i wouldn’t say that the quality can make up for quantity in this case.
That’s not what you said though, you said Linux users would be no customer at all, that was never true.
Proton made the responsibility for support change from the Developers to Valve, and meant that Developers no longer cared to support Linux directly.
Be that good or bad or whatever.