The claims of the Witnesses have been all over the board since the beginning. They've never, ever, claimed to be led by revelation as the ancient apostles were; yet they've wanted to be thought of as modern apostles (meaning "sent ones"). As far as I know, none of them has ever claimed to see God, or an angel, so to claim being commissioned of God is not something they profess. As strange as it sounds, their primary assertion that they're God's church is humorous to many. Simply put, without any scriptures or purported revelations to back them up, they say that in 1919 Jesus examined all the religions of the earth. He then chose the Watchtower Society as being the one closest to the truth and he rubber stamped it. From then on, God and the church were formally engaged.
And ever since, they've been inviting everyone to the wedding!
It's almost impossible to get a one-up on God, but that year he found that he was engaged and he hadn't even bought a ring. And ever since the JWs have been telling everyone who will listen that the wedding date will be any day now. Go ahead and spend your pensions! You kids, don't even think of higher education! Millions alive will never die! And don't forget your meetings and tracting obligations!
How they can make the claim of Jesus inspecting the earth's religions is beyond me. It's not in the scriptures, and Amos wrote that "surely the Lord God will do nothing save he reveal it to his servants the prophets." (Amos 3:7) The question becomes: Is the Governing Body as a whole a "prophet"? I don't know if they've gone that far or not, but they've come close to implying it.