Nope, I didn't say that.
Nobody has to feel sorry for a corporation, also nobody without a video games background might think this wasn't made by Nintendo, don't think too highly of the general population though.
Literally the whole thing with Dreams is that it's a platform where anyone can put up their creations. Pretty sure people playing Dreams stuff are aware that the fanart on it isn't made by the corporations that own the franchises.
Unless you're seriously saying people think that the creations featuring Shrek, Rick & Morty, Wallace & Gromit, and Peter Griffin are collaborations between Dreamworks, Adult Swim, Aardman, and Fox.
I mean, maybe there's some kids who'll think that the original creators had some sort of involvement but not nearly to the point where people generally think these are official creations.
And regardless, I don't really think it matters.