Canon has now confirmed that the update/fix will come in January 2020.
It has been confirmed that when using the RF70-200mm F2.8 L IS USM to perform AF shooting to capture a subject at close-range with the focus distance approximately set to the Tele-end (200mm), the image may become slightly front-focused.
New firmware with improved focus accuracy is scheduled for release in the beginning of January 2020, and once the preparations are completed, we will post the information on our website.
Note: New firmware being released at this time is for lenses equipped with firmware version 1.0.5 or earlier. The lens firmware version can be checked in the camera’s menu.