Not recorded means very little. We have a few New Testament pages in red. Does that mean Jesus only spoke then? Hardly.
He speaks what the Father has commanded, even now to those on His side of the veil and to the Prophets on this side of the veil.
Limiting his voice, the voice of the Father, or the still small voice of the Holy Spirit, to Biblical verses only is in my opinion the height of Pharisaical thinking.
...and what of the thousands of prophets throughout the ages, given great responsibility for their dispensations and in some cases not having tasted death? Would they not be just as engaged with those passed into eternity to bring them around from their earthly thinking, to a belief in the Lamb of God? The work of saving souls does not stop, anymore than the voices of God the Father and his only begotten in the flesh.
I have a pretty good idea that what Peter wrote here is quite good enough for most people; who have no itching ears for more; More; MORE!