Célestin Matte, Mathieu Cunche, Vincent Toubiana; Does disabling Wi-Fi prevent my Android phone from sending Wi-Fi frames?; Technical Report, RR-9089, hal-01575519; INRIA; 2017-08-21; 15 pages.
tl;dr → No. Betteridge’s Law.
No. We show that another option, called “Always allow scanning”, when activated, makes a device send Wi-Fi frames which can be used to track this device, even if the Wi-Fi switch is off. This option is not clearly described in all Android versions, and sometimes even not deactivatable. Besides, the Google Maps application prompts the user to activate this option.