I don't think(?) eBay globally banned selling of past copies of Meinkampf while the copyright was cleverly held by a German State. Doing so is pretending copyright is a right that extends to sold property that is a copy, extending a right too far, while banning a class of books like MeinKampf for your own reasons is perfectly valid.
If they want to ban racist children's media on their platform then they should. That includes a lot of TinTin, popeye, Tom and Jerry, etc, that has never been classified as racist by some copyright holder.
edit- s/published/printed
Of course, if you believe that copyright should prevent the resale of goods, that's an entirely different story that ignores the current state of affairs in the world and the legislated rights of people in many countries (where there are such laws that prohibit limiting the resale of goods).