Bafh, you are right, the "no duress/undue-influence" statement was there before, however, you could easily sign it and throw it away. This is exactly what I did for many years when I was in.
This time, its different: The brothers and sisters receive the instruction to make at least three (3) photocopies: Two for the two witnesses that signed it and one for the secretary of the congregation. In addition, to ensure absolute compliance, they even request access to your medical records! Hence, the "no duress/undue-influence" statement cannot possibly be true today!
Now, how could not signing this ADD derail all the way to disfellowshipping? Imagine this: The secretary of the congregation repeatedly ask a brother for his photocopies: "Don't take it wrong brother, but it feels like you don't want to make photocopies. We have a photocopier right here in the hall, I can help you with this. This arrangement is made to protect you. Why would you reject it? Do you at least keep your card with you?" With unceasing questioning, the brother could become exasperated and tell the Elder that he doesn't believe in the blood doctrine and won't carry the card, nor make photocopies. With loving kindness, the Elder than visit the brother with a second elder to help him come to his senses. As those Elders are unable to convince the brother who has been lead astray, they then form a comity for Apostasy. This scenario is not all that far fetched.
15 years ago, a brother looked into my wallet (while I paid for something) and noticed I didn't have my ADD. He brought one at the following meeting where I signed it on the spot with two witnesses. Today, I realize that this was "undue influence". But at least, I still had the option to threw that newly signed card away. Today, they want photocopies and your medical record! I think that there is room for legal matter over this.
If anyone has copies of the Canadian instructions and Cards, please let me know as I think I will bring this to the attention of my local hospitals.