Some of the wording is kind of worrying. They're not going to shake people down for streaming/uploading Nintendo stuff anymore, but they've thrown a couple of things in there that weren't there in the previous list of guidelines.
You are only permitted to use Nintendo Game Content that has been officially released
Uploading and livestreaming Nintendo Game Content from a Nintendo-authorized or licensed tournament is within the scope of and subject to the Guidelines. However, hosting a tournament is a separate activity that is outside the scope of the Guidelines.
Examples of unlawful, infringing, or inappropriate content include, but are not limited to, content that incorporates Nintendo intellectual property and ... Features pirated Nintendo software.
We reserve the right to remove any content that we believe is unlawful, infringing, inappropriate, or not in line with the Guidelines
The first point raises questions about whether things such as fan made games or romhacks would fall under this rule. The second makes it seem like they're going to try and pull stuff like Smash tournaments not endorsed by Nintendo, and could maybe even apply to various speedrunning events, as most of the games, particularly US events/marathons are mostly Nintendo based. Finally, pirated stuff is obviously illegal, but they have never specified that they would go after video/streaming content that includes it.
Someone needs to step up and sue the shit out of them, because what they're doing is still a violation of fair use laws. This time they aren't even just specifying that these things apply to people monetising videos, the wording makes it seem as though this applies to any Nintendo content regardless.
Yeah, it's pretty bullshit wording that is hopefully only there to cover their ass for "we can enforce whatever we want, but probably won't most of the time"
Translation: upskirt shots of Peach will be removed