How can lane changing assist help you in this situation without steering override?

Your answer is correct. The lane changing assist in this situation provides a warning of a possible collision with a vehicle in the middle lane. According to German traffic rules, this system helps the driver by alerting them when another vehicle is in their blind spot or close enough to make a lane change risky. However, it does not independently perform the lane change or apply the brakes. The driver remains fully responsible for steering and controlling the vehicle. This warning function improves safety by increasing the driver's awareness of surrounding traffic before making a lane change.