http://www.nintendolife.com/news/2013/11/talking_point_regional_online_multiplayer_misses_the_point
Nintendo locked multiplayer behind regions and your geolocation for Wii Sports U and Mario Tennis before.
I assume this is just a system wide implementation of that for all games and their ownership.
Wii Sports U is not region locked by IP, I have a US Wii U in London and can play it just fine online. Mario Tennis Open however, the online mode is locked by IP, which is completely idiotic.