Welcome to the world of information, where viral images will blast across social media and reach tons and tons of people, so long as they're tinged with humor, irony, or any of those other Shareable Qualities that 2014's Viral Experts love.
Sadly, these images are almost never accurate. They're always missing some information, or some context, that makes them seem funnier or stupider than they actually are.
Look at this tweet, for example, created by an account named @VIDEOGAMES that seems to exist only to spread viral images. It has over 4,000 retweets, and has likely been seen by tens of thousands of people.
Hilarious, right? Ubisoft's so incompetent that they filed a copyright claim on their own YouTube channel?
But no—despite all those retweets, one glance at UbisoftUK makes it clear that this is a non-official YouTube account with nothing but six subscribers and a couple of old videos. On top of that, there is no Far Cry 4 trailer yet—all we've seen so far is the box art. Any trailer on the web right now is either fake or leaked, and in both of those cases, Ubisoft would certainly have reason to file a claim.
So, no, Ubisoft didn't file a copyright claim against themselves; they filed a copyright claim against a fake channel for what was likely a fake video. But thanks to the power of viral images, thousands of people now likely believe that the big ol' dumb publisher is doing big ol' dumb things.
The lesson: as always, be skeptical of everything you see. Especially viral images.