The Horror the horror
Banned
All games indirectly compete for the same dollars, but that's not as much of an issue. All games compete for advertising directly. Therefore, competing in Fall means either Ubisoft pays more for ads or shows fewer ads at worse times.
Not only that, but will Ubisoft be willing to pay premium for those scarce ad spots?
Having worked at Gamestop, I can tell you right now that even in the unlikely event Ubisoft elects to aggressively advertise Rayman this September, retail outlets might not be swayed, because, in the end, it's about which ads will bring the most customers through the doors, and it isn't Rayman. This September will be predominately GTA5 and Madden 14. Everything else will be fighting for scraps.