quadcopter, what device do you use to fly your drone, attached to the RC? If you use your mobile phone, or any other device attached to a mobile network then it is quite possible that DJI can access data on that device.
I use a dedicated Nvidia tablet with no SIM in it so there is no way DJI or anybody else can access it. Neither the Drone or the RC unit has the facility to "transmit" data anywhere other than between themselves.
I am sure DJI is not "monitoring" every communication between drones & RC's and even if they di, so what, they'd find out where you were flying.