The Magic Mouse just got a minor update where they removed the batteries casing in favor of an internal rechargeable battery. Maybe also update on Bluetooth radios, not sure. It did not get Force Touch, as it’s Trackpad cousin. Or a new design.
Apple is clearly favoring the Trackpad as the de-facto Mac point and clicking tool and setting the Mouse as the entry point peripheral.
This update doesn’t even deserve the "2" on it’s name.