I found a few quotes. I think to assume they haven't seen him is based on nothing but opinion. Their testimonies seem to say otherwise. I'm sure there are many more than this, but its what I was able to quickly find
As one of those called as special witnesses, I add my testimony to those of fellow Apostles: He lives! He lives with resurrected body. There is no truth or fact of which I am more assured, or know better by personal experience, than the truth of the literal resurrection of our Lord.[1]- Ezra Taft Benson
And so on the third day following His burial, He came forth from the tomb alive and showed Himself to many. There were witnesses then who saw Him. There have been many in this dispensation who have seen Him. As one of those special witnesses…I testify to you that He lives. He lives with a resurrected body.[2] - Ezra Taft Benson
‘He [Elder Brown] said it was not a vision, but the Lord appeared to him, very informal, the same as I was sitting talking to him. The Lord said, ‘You have had some difficult times in your life.’ Uncle Hugh responded, ‘Yes, and your life was more difficult than any of us have had.’ In the conversation Uncle Hugh asked when he would be finished here, and the Lord said, ‘I don’t know and I wouldn’t tell you if I did.’ Then He said, ‘Remain faithful to the end, and everything will be all right.’[3]- Hugh B. Brown
Mine is the certain knowledge that Jesus is our divine Savior, Redeemer, and the son of God the Father. I know of his reality by a sure perception so sacred I cannot give utterance to it. I know and testify with an absolute awareness that Joseph Smith restored the keys of the fulness of times and that every President of the Church has held those keys, as does President Gordon B. Hinckley today.[5]- James E. Faust
I know that this is the Lord’s work. I know that Jesus Christ lives, and that he is closer to this Church and appears more often in holy places than any of us realize, excepting those to whom he makes personal appearance.[9] - Harold B. Lee
Why don't our talks in general conference and local meetings say more about the miracles we have seen? Most of the miracles we experience are not to be shared. Consistent with the teachings of the scriptures, we hold them sacred and share them only when the Spirit prompts us to do so…In bearing testimonies and in our public addresses we rarely mention our most miraculous experiences, and we rarely rely on signs that the gospel is true. We usually just affirm our testimony of the truthfulness of the restored gospel and give few details on how we obtained it. Why is this? Signs _follow_ those that believe. Seeking a miracle to convert someone is improper sign seeking. By the same token, it is usually inappropriate to recite miraculous circumstances to a general audience that includes people with very different levels of spiritual maturity. To a general audience, miracles will be faith-reinforcing for some but an inappropriate sign for others.[12]
Visions do happen. Voices are heard from beyond the veil. I know this. But these experiences are exceptional. And those who have these great and exceptional experiences rarely speak of them publicly because we are instructed not to do so (see D&C 63:64) and because we understand that the channels of revelation will be closed if we show these things before the world.[13] - Dallin H. Oaks
[In his journal, Marion G. Romney wrote:] I don't know just how to answer people when they ask the question, "Have you seen the Lord?" I think that the witness that I have and the witness that each of us has, and the details of how it came, are too sacred to tell. I have never told anybody some of the experiences I have had, not even my wife. I know that God lives. I not only know that he lives, but I know him.[23] - Marion G. Romney
In conclusion, please be assured that senior Church leaders who preside over the divinely appointed purposes of the Church receive divine assistance. This guidance comes from the Spirit and sometimes directly from the Savior. Both kinds of spiritual guidance are given. I am grateful to have received such assistance.[27]- Quentin L. Cook