Nintendo is back at it again using automated services (this time Tracer AI which they had used to take down the fangame site Relic Castle instead of MarkMonitor) to remove NSFW artwork of their characters from Twitter. This isn't the first time something of the nature happened, previously it happened in 2019-2021, 2016, 2014, and 1999 under various circumstances. It's probably not going to be the last either.
Currently Devil Voxy and SaltyXodium have been confirmed to receive notices, along with a few others, predominantly paysite artists (similar pattern as the 2019-2021 incident). It's unknown if hobbyists have been effected, though they were last time. I can at least say I haven't received a notice (not that I won't fight it if I do, as I've helped others do in the past) being a hobbyist.
I would also like to add this is not something new. Nintendo has been harassing us NSFW artists for a long time now. I expect many people to throw in the towel like last time but also many to just do the usual dance of new account creation (mostly hobbyists, paysite artists will all cave). Personally I'm not taking any of Nintendo's shit if they strike me, I started drawing Poképorn directly as a result of the last incident in part to spite them and I'm not going to stop regardless of what they threaten me with.
Updated