There would be at least service gaps if you changed MAC on the fly while connected to a network. At worst your packets would go to another device, unless your device announced it's MAC change, which would render the whole operation pointless.

And sniffing for probe requests is way more revealing than just sniffing MAC addresses. Only real solution is to turn off all WiFi and bluetooth devices, latter is getting harder and harder with smart watches, wireless headphones and other stuff.

That being said I'm not worried about being tracked while I move through an airport, since they already have cameras. Also your ticket is pretty telling, they know when it gets printed out, when it gets scanned in security and when it's scanned in the boarding, so you have always been tracked. This just brings more accurate data how long it takes for you to get from point A to B.