Did Joseph Smith go to heaven according to Protestant Trinitarians?

According to the [Mormon Doctrine](https://archive.org/details/MormonDoctrine1966/page/472/mode/2up) written by Bruce McConkie, >If it had not been for Joseph Smith and the restoration, there would be no salvation. There is no salvation outside The Church of Jesus Christ of Latter-day Saints. But Paul says: "...Believe in the Lord Jesus, and you will be saved..." (Acts 16:31) Is it mutually exclusive? Could Joseph Smith have gone to heaven according to the NT, obviously extending to all members of the Church of Jesus Christ of Latter-Day Saints? Protestant tradition may used as the starting point of the answer, although biblical support would be much appreciated.