Comment by csomar
You can only realize the tax if the stock owners sell the stock (vs. giving them a dividend which triggers the tax on payment). It is more of a tax delay but since many people who bought these stocks have more money than they need, they no longer need to sell and they don't need the dividends much. So a buyback is just injecting that money back into their shares tax-free.
Yes, that's sort of what I thought must be happening. There's no "trick" involved. It's like saying salaries are a "trick" to avoid dividend tax. They'll still pay tax on it when they sell it.