But they weren't, during the Gamecube era Nintendo was rushing games out in order to meet dates for that system as well. Nintendo made it clear over a decade ago they will rush games out if their system is struggling and needs games. I agree it's sad much of the industry is releasing unfinished games that they just fix later but Nintendo releasing unfinished games to help fill their schedule isn't really a new thing.
I don't know, man. You mentioned Wind Waker in your previous post, and called it "incomplete forever." Nintendo updated the game a year and a half ago, and if it considered the game incomplete, it could have easily inserted additional content outside of tweaks like the swift sail. I suppose it's possible that, given Wii U's obscene lack of first party titles at the time, Wind Waker HD was also rushed, giving that game the unique distinction of being rushed twice.
When I said, "Nintendo was like the last holdout," I was specifically referring to the oh-we'll-fix-that-later attitude that has become common in this industry. Every game has content cut for a variety of reasons. Comparing Wind Waker to Splatoon is problematic due to the kind of content they're missing. I would have loved another dungeon or two in Wind Waker, notably instead of Jabun giving Link Nayru's Pearl. However, I'd argue that Splatoon's post-release patch is content the game shouldn't release without given the type of game it is. I'd hate for this to be the first step in Nintendo eventually deliberately releasing a broken game with the intent of patching it later.