We contacted 2K Sports and they said there were discussions about keeping OJ Simpson out of the game, but it eventually ended up that being a football legend, the man deserved to be in there. As for the whole Assassin thing, they didn't have an NFL license and consequently made up team names, one of them being the Assassins. They say you go through the character selection screen and you can make the team any way you want, it just happened that the two elements put together make for an incredibly awkward moment. Now, here is the key element to all of this: We asked, "Did 2K make the video for GameTrailers, therefore it being possible for [2K] to be implicated as having some hand in creating controversy?"
The 2K Sports spokesperson said, "No, to the best of my knowledge, we didn't make that video." A second call from 2K Sports confirms that they did not make the video.
So, if the drama does escalate from this point, it'll either be due to 2K having actually made the video, or people riding the wave of outrage over OJ Simpson's appearance in the game.
Update: 2K Sports states clearly they did not make the video.