We used the AP only line again today at Epcot. Efficient, but today there was a new twist. Before going to the touch points they had a cast member asking to see your annual pass card because "anyone could claim they are a pass holder". Luckily we had ours with us. Seems to me it would show up when you scanned at the touch point if you were a pass holder or not.
As we were exiting the touch points, we overheard a manager telling another cast member that "guests either need their card, or the slider on their MagicBand that shows they are a pass holder". The first cast member we encountered didn't seem to know that the slider was acceptable for ID, so apparently Disney is still working out the kinks in this system.
Since they didn't actually scan the card, and the cards have looked the same for at least several years, I could have shown the cast member any old card.
I wish if Disney was going to use MagicBands that they would go to them fully. We still have to carry our cards around to get restaurant discounts, and now apparently to get through the AP only lines. One more thing to keep up with.