They do a lot of puns in their tweets, and this one, too, was meant to be funny. But when they realized the joke didn't "sleigh" anybody, they deleted it. Some jokes work, some don't.
It possibly would have went over better if they would have used a similar word like Sledding instead of shredding. But people might not have understood the joke. Some people, myself included, didn't know this was meant as a joke either. It was almost like some overworked UPS worker went on the twitter account and vented about something that annoys them about their job; receiving children's letters addressed to the north pole.They do a lot of puns in their tweets, and this one, too, was meant to be funny. But when they realized the joke didn't "sleigh" anybody, they deleted it. Some jokes work, some don't.