The whole message on the site makes no sense and I think that's on purpose. What likely happened is the US gov found the TC authors, then used their weight to try and get them to back door the binaries. Authors didn't want to, but couldn't publicize the letters without going to jail, so they made up the most ridiculous story for why they were giving up on the project, the best possible outcome so that they wouldn't go to jail and wouldn't subject users to the required back door.