While I see DXVK was important, Valve’s history with Linux is much older. I would place “anime girl thighs” on the second domino
SteamOS was first released in 2013, just before they released there first hardware running Linux, the duly forgotten Steam Machines in 2015.
It doesn’t help much if your cousins signed up with their real name. If you are male, they can figure out your surname even if no close relative submitted samples: https://en.wikipedia.org/wiki/Surname_DNA_project