Getting back on topic, while it might not seem "fair" to be walked from a hotel, it happens. Regretfully the way the laws are written, there's not much a hotelier can do about it. In some cases when people overstay their reservation, it's becaues they are ill or have another "real" reason to stay on--bad weather cancels clights, etc.
Generally when a hotel walks a guest, they do so to a nicer property. If this happens to you, remember to negotiate. Here are a couple scenarios:
1. It should be your choice whether to move for one night or stay in the new room the entire time. if you choose to not move again, then they should not expect you to pay any additional fees over the original room rate, even if they move you from the AS to the GF.
2. If you are willing to move to a different hotel for only one night, then come back to the originally booked hotel, the first night should be comped, ie free. They should refund the entire cost of room and tax for the first night.
3. If they move you to a "lower" hotel for one night they should comp the first night and give you something else for your troubles--a fruit basket, free park tickets, it's negotiable.
4. If they move you to a lower hotel for your entire trip, they should comp the entire room charges. You can also negotioate for other perks.
5. Regardless of where they move you, make sure that they pay for any additional transportation. If you arrive via shuttle or towncar and they walk you, they must either transport your via their shuttle van or pay cab fare and tip to the new hotel. Same to move back the next day if this is what you decide to do. You do not need to accept "we'll move your luggage, you can take WDW transportation" between hotels, you have the right to demand to travel between them with your bags with you, on the walking hotels dime. They should also pay the cost of making a long distance phone call to let someone at home know that you've been moved.
These are all industry standards. Hold your ground, but be calm and polite, and remember, negotiate, negotiate, negotiate. If I were in the OP's shoes, I would have let them walk me to a deluxe, on the condition that they allow me to stay there for my entire trip at the rate I was paying for the AS's. Or to a moderate at the same rate plus some other perk. I would not have accepted a one night walk.
I used to travel 300 nights a year with my job. I often purposely booked hotels that I knew were going to be oversold in order to get walked to nicer properties. It was great paying for a Sheraton and staying at the Ritz Carlton! One time I got a four night stay at the Four Seasons comped because I got walked from another hotel for the second time in four months, plus they sent me flowers!
Anne