Perhaps this news release is well-timed & just prior to the buyback offer to ensure that they get enough investors to offer the maximum amount of shares repurchased at the lowest price (i.e. $8.30)! Then watch the price go up after January 23.
Just because the Company is buying at 8.30 doesn't mean anyone else would. The question is: after the buyback, who will be buying the stock? Given the relative outperformance a trade that is short miners is probably better off shorting AUQ than GDX.