I watched the video from my compatriot on how to legally end the WT. I do not think that would end it even if he is successful. Sometimes opposition only makes the cult prosper.
If the WT non-profit status is taken away they would just pass on the cost to the Rank-and-File witness to cover it, and ask them for more and more contributions.
I think the only way to end the cult would be for it not to get any money from members, zero. But they could last for a long time by cutting down and living off the interest and real-estate asset holdings they could liquidate. And, there would always be some who would fall for their tricks and keep supporting them even when it hurts them personally that is financially in life.