That works as long as you make sure that Magic Band is on the ride. If the person wearing the band skips a ride (or the person who has it in their bag doesn't remember to hand it off to someone else), those photos won't be captured. You can still use Bluetooth or hit the tap point at the end of the ride (though not all rides have that option anymore). Just something people need to keep in mind when using this method.
If you are going to Disneyland (California) be sure to note that Disneyland only uses the MagicBand+ (the newer ones) - just good to know in case you are thinking of buying any new bands.