Read the article. Headline is a bit deceiving. The family doesn't have to pay taxes on the money they don't have because they gave it away.

Sort of like the huge tax savings I accrued by not winning the lottery. I saved millions in taxes by not winning the billion dollar powerball.

Likewise I could have won the powerball billion, given it all away and saved millions in taxes- I wouldn't be getting wealthier by reducing my taxes.