Looks like Microsoft is trying to sweeten the deal for their Xbox Series S/X consoles with Sony's recent drop on PS5. On all/any Xbox bundles, you now get a choice of either a black or white Xbox controller additional included (for a total of 2)
They've also dropped the price of the Xbox Series X Diablo IV bundle by $20 to $829 which also comes with a free additional controller.
Works great with the Amex (targeted) offer of spend $550 to get $100 back if eligble.
That and clearing out the old stock before the new controllers come in