Where do you get the notion that freedom OF religion means freedom FROM religions? The document means absolutely nothing to the WTBTS, they will still go through their procedure of disfellowshipping you. And you cannot stop them, because legally that would interfere with their freedom OF religion, and that has been established as a legal matter the US, the EU and Canada.
In the letter you are basically stating that you have Human Rights, but having those rights does not mean Disfellowshipping has been made illegal. It has been made illegal in places like Russia and China though, so if you can make claim to that nationality and jurisdiction, you can actually claim that it would be illegal to DF you based on local laws that affect the family union.
The only way to stop a DF is to get a restraining order, but you need to have actual legal grounds, but that is very technical and dependent on what happened before. You still can’t decide you can stop them from speaking though, but a restraining order will hold them back. I was able to stop them from disfellowshipping me because the elders were family members of my ex, the elders stalked me to catch me in “wrongdoing” and I got a temporary restraining order against the organization doing “anything to affect the relationship with my child”, so they simply gave up.
Eventually though they simply circulated I was an apostate but never went through the process of inviting me to a disfellowshipping meeting, so technically speaking, I was never DF’ed or demoted from my position, since that was never announced, I’m sure my record is in a red folder though (provided they still use red folders for legal issues).