Not completely true. A poorly shielded and cheap electronic device can interfere with an aircraft electrical system. Understandably the circumstances are very rare and usually unlikely, however working as a technician for over 20 years (with a good portion of that in avionics) I have seen it happen.
A more likely situation though is the aircraft’s transmitters and radar systems causing problems with your consumer electronics.
Reminds me of a story related to aviation. Years ago we hired on a new PHD. His first job was to go to Omaha to figure out why the automatic foaming system was going off and "cleaning" the airborne command center which was parked in the hanger. This turned out to be expensive in foam and an inconvenience for the plane. What our man discovered was that during the ground check of the plane someone was keying the plane's high powered transmitter and overwhelming the control electronics for the foaming system.