To be clear, I'm not saying that this is what happened, merely floating it as a possibility, given the nature of BTC it wouldn't be hard to pull off.
Ah the good old  as a cover up for lack of basic research. Allow me point you to the SteamOS announcement page.
Where you will see under the (corny named) header 'Cooperating System' the line.
Users can alter or replace any part of the software or hardware they want. Gamers are empowered to join in the creation of the games they love. SteamOS will continue to evolve, but will remain an environment designed to foster these kinds of innovation.