I already linked to a case where this happened, here's another one:
https://www.greenmangaming.com/news...ft-drops-pubg-ad-fan-art-rip-off-controversy/
If you really think these things aren't removed for legal reasons you're being intentionally obtuse, "oh but you don't have legal expertise to back you up", well nobody has show legal expertise to refute my claims either anyways and examples of previous cases of fanart thievery and accidental misuse speak for themselves.
The plagiarism example you cited in your link is not what is being discussed here. It's a rip of an in game asset that has had a pixel altered.
The two situations are not the same. There's nothing to suggest that the altered pixel makes it a new protectable and copyrightable work. To have a valid copyright, you must show:
(1) originality in the author; (2) copyrightability of the subject matter; (3) a national point of attachment of the work, such as to permit a claim of copyright; (4) compliance with applicable statutory formalities... etc.
The originality of the author (the first element) is totally lacking here. There are probative similarities between Nintendo's original work and the ripped sprite with a pixel altered to ever allow it to rise to the standard of demonstrating "originality of the author."
If the person who ripped the sprite cannot claim any copyright infringment due their lack of originality then Nintendo is not in any dubious grounds by copying the ripped sprite which remains their intellectual property.
The link you provided, in contrast, is about copying something that is demonstrably original from the original author. That author did more than simply alter a pixel - they merged disparate concepts to form a brand new wholly original image.