Phillip the only problem with this method is that you are only getting a signal from one of the mic elements and not both. So in a sense you are losing all of the sound from the other mics axis. If you did this, then you're better off using a mono mic as it would be a waste of the AT822 stereo capability on a camera. Stick to the XLR Y cable.
There is a little switch by the mic inputs that shows a CH1 over a CH1,CH2 switch. Set it to the CH1,CH2 and it will lay down both audio channels on the tapes so it imports like it was recorded in Stereo. Check page 48 in your A1 manual.