Maybe not, but the argument was that it would sell the same amount of copies as The Last of Us remake, and I still totally disagree with that. I for one won't be buying either, as I've already played The Last of Us (and a minor graphical upgrade doesn't do anything for me) and I've played all the Halo single-player games and have always found the multi-player (outside of Halo 1 LAN parties, which were pretty fun back in high school) plodding and boring.
Also, Titanfall didn't help Microsoft sell too many units because a perfectly fine version of it was already on the 360 (which I still think was an idiotic move on Microsoft's part...they should have gotten an Xbone/PC exclusivity agreement in writing) while an equal version was on the PC. Unless you're someone like me who has some disposable income and likes to be an early adopter, why buy an Xbone for Titanfall (which was a pretty good game, by the way) when you can play a similar version on the 360 or an identical one on the PC? If it had been Xbone exclusive it absolutely would have moved some consoles simply by virtue of being one of the first next-gen killer apps.