Seems like the newer releases dont have this case shipping, but here is an older release with the quote.
Ive read this on a lot of their switch releases in the past!
https://limitedrungames.com/collections/nintendo/products/switch-limited-run-46-duck-game-preorder
“There is no limit on this item. Orders of 30 copies (or multiples of 30) will ship in factory sealed case packs.”