Sorry, I'm really not seeing the jump to "treason" here. I also think the author has a personal vendetta against Twitter based on the final sentence of the post, but regardless - they acknowledge that declaration of war is a congressional power, and that contempt of Congress is a possibility - but somehow this means that removal of a post from a member of the executive branch is treason?

Would the New York Times refusing to run a story about how war was declared be treason? What about CSPAN cutting away the broadcast in the middle of a war announcement?

I don't think so, in either case, and I don't think it's the case for Twitter either - because them not carrying the information doesn't change the material facts of the declaration. They're not interfering in an official congressional process in any capacity, because they're not part of an official congressional process.