ESPN Playbook spoke to Madden producer Yuri Bialoskursky about this and other omissions, and what the Wii U version has to make up for it. Bialoskursky said while he would have liked to include the Infinity Engine (procedurally generated physics to impact plays and animations) in Madden NFL 13, the challenges of working with new hardware made it impossible. He also said Madden Ultimate Team--an online feature which combines fantasy football with in-game challenges--will not appear this year, nor will online team play be implemented.
The game will let players use the Wii U Gamepad's touchscreen to quickly select plays as well as draw in new routes on the fly. "We were looking at ways we could bring these elements into the Wii U space and make it a much quicker experience," Bialoskursky said. Madden NFL 13 will also support local five-player multiplayer using the Wii U Gamepad, Pro Controller, and Wii Remote and Nunchuks. The game's Connected Careers mode, which lets players manage teams from their browsers, will also be implemented.
Reading this closely, it doesn't say that there is no online multiplayer. Team Play is the online co-op/ 2 vs. 2 players mode, is it not?
My knee jerk reaction was that there is no online multiplayer for Madden NFL 13 on the Wii U but I was mistaken. So, I guess we can take this as confirmation that there is some sort of infrastructure in place for online multiplayer? Or at least enough for EA Tiburon to use it.