Have been re-reading that site and to me the text is being conveyed in quite a different way which also matches my own experience: This group is not demanding exclusivity for themselves, but actually inspiring people to do their own research with an open but scrutinizing mind, and to network.Don't you think that the statement "The only true ones" together with the statement that "people are denied true knowledge" and "the world is moving away from the truth" and the suggestion to find answers in FOTCM is a good introduction to any sect? Wouldn't it be closer to the truth to say that "we strive wholeheartedly to live fully with the truths of the original Christians" ?
It helps to widen the perspective for many - something that is not in accordance to the wishes of the Powers That Be, as they want to keep people's awareness as narrow as possible. At the same time, this group honors the free will of people to gather knowledge and implement it as they see fit (or are ready) regarding their own individual situations.
As for other groups, I believe if there were ones working in similar ways like FOTCM, they already might have been trying to make contact. FWIW.