I believe FIFA is better off being released after the seasons start. They cover hundreds of teams. There are rosters to update after the transfer window ends, and team kits have to be updated, too. I end up playing FIFA daily all fall and winter, so I don't care about the demo.
While FIFA has huge sales numbers worldwide, EA's priority lies with getting all the major North American games lined up and shipped out. The North American retailers depend upon that product to make their sales numbers. Would it make more sense to ship NCAA in September? Would it make more sense to ship NHL around Halloween? Maybe. But EA has a steady strategy that is geared towards meeting retailers' needs. Madden's ship date was pushed back a couple of weeks this year, but it is still before the opener of the NFL season.