They are identifying a product. The mark "Ultimate Fighting" identifies and is synonomous with the UFC promotion.
You couldnt be more wrong about trademarking adjectives or verbs. If that was true, no one would have adjectives or verbs as registered trademarks. There is a review process used by the USPTO to approve registered trademarks. "Ultimate Fighting" is a registered trademark (not just a in use mark) so its cleared the USPTO registration process and was approved as a mark. The company Xerox has the mark 'xeroxing" trademarked. The term "xeroxing" is considered an adjective.
No offense but your analysis of this claim is extremely basic. You arent even considering likelihood of confusion or passing off which is considered different forms of infringement also. I'm an Intellectual Property attorney for a media company and I handle trademark claims and lawsuits every day. We have sued, threatened to sued and been sued over marks that were considered adjectives or verbs. We've won cases over marks that were adjectives or verbs.
The only argument that Ubi may make is that the use was purely descriptive but thats BS. The use of the mark was clearly to make a consumer think of the UFC and to use the UFC's notoriety to entice someone to purchase the game.