It is true. This only applies to people subject to US taxation (citizens and residents) and it doesn't matter where they dump the coins.

Yes, you owe the tax whether you sell or not. It is the same for U.S. stocks when a company goes public, original employees of the company are often given stock in the public company and they owe tax on the value of the stock on the day the company goes public whether they sell or not. This normally means they have to sell some of the stock to pay the taxes due.