After the recent upset caused by Canonical's plan to drop 32bit support in Ubuntu, then to turn around and change their plan due to the uproar caused by it, Valve now have a full statement out about their future support of Linux gaming.
Firstly, to get it out of the way, there's nothing to worry about here. Valve said they "remain committed to supporting Linux as a gaming platform", they're also "continuing to drive numerous driver and feature development efforts that we expect will help improve the gaming and desktop experience across all distributions" which they plan to talk more about later.
On the subject of Canonical's newer plan for Ubuntu 19.10 and onwards in regards to 32bit support, Valve said they're "not particularly excited about the removal of any existing functionality, but such a change to the plan is extremely welcome" and that it "seems likely that we will be able to continue to officially support Steam on Ubuntu".
However Arch Linux, Manjaro, Pop!_OS and Fedora all got direct mentions in this statement, when talking about how the Linux gaming landscape has changed and how there's a lot more options to have a good gaming experience. Valve said they will be working "closer" with more distributions but they have nothing to announce just yet on what exact distributions they will be officially supporting in future.
Also, if you're working on a distribution and you need a direct line with Valve, they suggested using this link.
You can see the full statement from Valve here.
Fantastic news, I will be completely honest, there was that little worry in the back of my mind that Valve would start pulling back but why would they? They've put a ridiculous amount of resources into our smaller platform, things have improved an astonishing amount since Steam arrived on Linux back in 2013 and it sounds like things will continue getting better.