Hmmm, so 4 queues for one ride. A normal queue, a Express queue (if there is one), single riders AND a queue for people who can't exit the ride because they didn't pay for a 2 park ticket...I hope they do serve meals on this train because you sure will be waiting a lot to get onto this ride.
I sort of see how they could get rid of the single park ticket and make it mandatory to get a 2 park ticket. Sure, that might scare some people away when they are forced to pay $150, like you said, but I see any other way either being massive confusion or just an endless queue for a simple train ride. I'm not a huge Harry Potter fan so I'm not sure if all this fuss is worth it for a monorail ride...but whatever. We'll see what they do.