Honestly.. all CoD will do is highlight just how much better Titanfall is :/ For all the shit Respawn got over the tech test, the game is still leagues above anything COD has put out recently.
Titanfall can still do "fine" but EA needs to get behind it bigtime and give it a huge marketing push over the holidays. Respawn needs to do what they can to keep it being talked about (announce free DLC plans, etc). Make it a game people ask for their Christmas, not a game that most people don't even know released yet.
The game is out, it's better than CoD, it's got very good reviews and will no doubt have good word of mouth. It's up to EA to market the hell out of it and make people want it for Christmas now and give the game strong legs. Unfortunately I seriously doubt thats going to happen considering they've barely done anything so far and... I mean, there's a FIFA bundle this holiday but not a Titanfall bundle?
Problem is this year MWR will absolutely save the game. Without it IW would be in the worst position of any cod ever in my opinion, but with MWR bundled it's still going to sell well and sadly will probably make Acti boast about how great the game sold.
I have multiple friends just in my circle who are passing on Titanfall because the beta didn't wow any of them and "next week is MWR".