I'm surprised Nintendo doesn't sensor. They wouldn't want to damage their family brand they've work so hard to create. I guess they really want the 3rd parties on board.
Nintendo hasn't censored 3rd party games in decades. The first time the gaming media took note of this was BMX XXX, it's a terrible game but the Gamecube version was the only one uncensored. Players could get rewarded with video of topless women. This was censored in the PS2 and Xbox version. You maybe confusing Nintendo changing the localizations on some of their first party titles.