I doubt Harada actually did anything and probably just tweeted that to scare people; I believe he’s done similar before, iirc someone mentioned that when his tweet was more relevant, and what caused him to do that was one guy in a ForSmash meme chain tagging him and Sakurai with an Infinity War meme, and nobody noticing the tags when further replying memes until Harada tweeted that in response. (spamming devs was not the intention of those participating in the meme chain, no one noticed the random dude’s meme having those tags; he wasn’t a ForSmash account, either)
Other ForSmash accounts were also part of the meme chain, including Steve’s iirc, so if Harada actually tried to do anything, Nintendo and Sakurai likely didn’t care.
Also, this argument against Reimu based on ZUN not having the same views on fanworks as Nintendo is complete nonsense. It’s none of Nintendo’s business, I doubt they care how others treat their IPs as long as it’s not infringing on Nintendo’s own.