I guess you missed the post above where the guy said it clearly stated on the GMG page it used Telltale DRM?
You mean this one?
http://www.neogaf.com/forum/showpost.php?p=93962095&postcount=147
Thought he was referring to TWAU. If he was referring to TWD and other people complained that it didn't state whether it was TT or steam DRM, GMG could have left it blank initially then changed it to TT DRM later on.