It's not apples to oranges. God has been calling preachers since the cannon was closed. So Him calling one more is not a "new revelation".

I disagree about the audible voice in the others. What else could it mean? The one I gave in 1 Kings was also an audible voice. It was merely instructions for Elijah. There seems to be a biblical difference between hearing the voice of God and having the "Word of the Lord come onto" someone. The latter is clearly for prophesy and would be new revelation. The former is just instruction.