It wasn't a mistake, it's a sign of the times. They shouldn't even be making and promoting "Wicked" dolls for 4 year old, much less printing porn sites on their boxes.

https://www.cbsnews.com/news/wicked-dolls-mattel-pornography/

Only people mentioned by @GaDawg3 in this post can reply

"Come now, and let us reason together, saith the Lord" Is1:18;

In response UM EK17 Q1111 to his Publication

Wasn't a "misprint" or "bad link" ... the website was clearly printed as exactly how it *would* have been if it was the *right* one ... thus it *was* the right one.
Now someone could have hacked the site and misdirected the incoming traffic to that porn site (I *think*?) but Disney isn't even claiming that so what does that leave one to surmise?