Just got notification of this yesterday through Carfax although it was published on May 14. Usually it takes the manufacturer a few weeks plus to send letters out and the remedy's not ready yet. This pertains to US-based vehicles only, although I imagine if this were a global issue each country will end up announcing their own recalls.

You can check your VIN here on the NHTSA website. I checked and my October 2020 build is affected.

May 14, 2021
Manufacturer Recall Number 2021050010
NHTSA Recall Number 21V353

Recall Status
Recall Incomplete, remedy not yet available

Summary
Mercedes-Benz AG ("MBAG"), the manufacturer of Mercedes-Benz vehicles, has determined that on certain Model Year ("MY") 2019-2021 G-Class (463 platform) vehicles equipped with rear door latches for the US market, the rear doors might not open, close, or lock according to current production specifications. Depending on the tolerances of the components within the latches the rear doors might not be fully closed even though they appear to be closed, and could open while driving under certain types of driving maneuvers and road conditions, increasing the risk of a crash or injury. Further, if the child safety lock is activated on the rear doors and excessive force is used to attempt to open the doors from inside the vehicle, the internal latching components may deform and prevent the rear doors from being opened from the inside, increasing the risk of injury in the event of a crash. An authorized Mercedes-Benz dealer will replace all the rear door latches on the affected vehicles with a door latch that incorporates an enhanced design, including those previously replaced or repaired under warranty.

Safety Risk
Depending on the tolerances of the components within the latches the rear doors might not be fully closed even though they appear to be closed, and could open while driving under certain types of driving maneuvers and road conditions, increasing the risk of a crash or injury. Further, if the child safety lock is activated on the rear doors and excessive force is used to attempt to open the doors from inside the vehicle, the internal latching components may deform and prevent the rear doors from being opened from the inside, increasing the risk of injury in the event of a crash.

Remedy
An authorized Mercedes-Benz dealer will replace all the rear door latches on the affected vehicles with a door latch that incorporates an enhanced design, including those previously replaced or repaired under warranty.

 

The fix is ready -- took the dealer only minutes to repair.

 

This happened to mine. The dealer fixed it with a new lock mechanism/.

 

Here are my car ownership experiences with safety recalls over the past 35 years:
Nissan 3 vehicles 19 car-years 0 recalls
BMW 5 vehicles 30 car-years 0 recalls
Jeep 2 vehicles 30 car-years 2 recalls
Lexus 3 vehicles 20 car-years 1 recall
MB 1 vehicle 2 car-years 5 recalls