I know why this statement was made. And no, it has nothing to do with that exhibit, not really.
People, meet 'Musti'.
This is Musti. A white cat from Belgium, Flanders to be exact. Created by Ray Goossens in 1945. It's spanned an entire franchise spanning decades, making his first tv appearance in 1968. (Hello kitty wouldn't exist until 1974) There are also children's books, games, and a ton of merchandise.
He's a pretty big deal in Belgium and the Netherlands to a lesser extent.
The problem here, though, is that recently many people have started to see the uncanny resemblance between our Musti and the Japanese kitty Howaito.
The people holding the Musti licence doesn't seem to care all that much, but since the Japanese company Sanrio caught wind of the Musti character (most likely because Kitty IS just a Japanese gender-swap) and seem to be scared to get their pants sues off.
With this 'it's not a cat' excuse, they're kind of in the clear on the whole copyright issue, seeing how kitty is not even a cat. (Big companies can bullshit their way out of everything.)