Interesting.. I did a little digging, and this seems.. not entirely accurate.
They paid Vox to put ads all over the documentary. The doc contains a bunch of IE9 advertisements.. this happened way before the consoles were out, and has kinda nothing to do with their editorial department.
Sony also buys / has bought ads from Polygon.
In fact Sony helped them launch by being one of their major backers, and must have had some sort of similar video advertising:
The behind-the-scenes story of Vox Media's ambitious new video gaming blog.
www.forbes.com
So yes.. MS bought ads on Polygon... their early attempt at making money involved selling ads on video series.. apparently Sony did the same.
You guys gonna stop spreading the conspiracy theory?
Probably not lol