Yeah I certainly need actual confirmation, and will likely reach out to their support team for an answer.
Primarily, my MCN(Multi-Channel Network), requires me to have permission(as technically everyone does, but most do it anyways).
Most developers provide something like this: http://thewitcher.com/en/videopolicy and I few I've had to reach out to their support for them to give the go-ahead.
and it's worth noting, that greybox has had a statement on their greygoo forums saying it is allowed ( https://www.greybox.com/greygoo/en/forum/topic/249/ ), but that is greygoo, and when companies like EA, and Microsoft provide different permissions for different games, then I can't use that.
As far as your comment about negative advertising, a while back(2-3 years ago), SEGA issued copyright infringement strikes to all YouTube videos with SEGA games in them(including the entire Total War Series, Company of Heroes, etc, among other games). And since then, YouTube, and MCN's have really tightened up the reins.
Primarily, because how MCN's work, if there is a copyright issue, it goes against them, not me. Because all videos are automatically claimed by the YouTuber's MCN, and this is how they handle monetization, ad-optimization, as well as copyright holding(so if someone else uploads your video that you already uploaded, your MCN leverages a copyright violation against them).
I'm going to actually send a email to support, and see what they say. I'll report back here if I remember.