EA have decided not to release Madden NFL 25 (no, you haven't stepped into a time travelling machine, it's to do with the 25 year anniversary) for Wii U. Last year's edition was released on Wii U at launch, but apparently sales have not been good enough to motivate a release this year.
EA Sports have previously opted out of Wii U editions for Tiger Woods PGA Tour 14 and NHL 14. Remains to be seen if EA change their tune if hardware sales pick up.