These controllers were all working on SteamOS before as far as I know, so I’m interested to see what this changes. My understanding is that previously their controllers just show up as generic xbox controllers, and now they will be properly recognized. We’ll see if this has any other benefits like custom bindings for back buttons and things like that.
https://fwupd.org/lvfs/devices/
In the devices list of lvfs/fwupd there’s a bunch of controllers supported. But it seems like it’s mostly their retro controllers. XBox-style controllers like their Ultimate C etc. are not supported.