Long story short, it appears that many users reported issues with their Intel Wi-Fi adapters not working after updating to the SteamOS 2.97 stable release announced on November 25. As such, the firmware-nonfree package was updated in SteamOS 2.98 to restore version 13 of the Intel wireless 8000C firmware. Two days later, on December 2, 2016, Valve promoted the SteamOS 2.98 update to the stable channel, which means that it recommends it to all users using SteamOS 2.97 or a previous version. SteamOS 2.0 build 98 was in fact generated on the 29th of November, but approved for general use a couple of hours ago.