pixelate, you wrote about the book Heaven is for Real where the author states he saw JC. I haven’t read the book. Did the person on the other side actually say he is JC? The Zohar tells us that we meet Adam (Hadam HaRishon) when we go to the other side (see Cave of Machpela). The author might believe it is JC when it could have been Adam.
Moses was on the other side and so were all our Sages, otherwise they wouldn’t be able to bring Torah knowledge and interpretations to the World of Lies we live in. Even the Lubavitcher Rebbe was there and he talked about it freely.
I think that the reason that OBEs and NDEs are happening so frequently now is because we are nearing a time when the knowledge of G-d will fill the earth and this is one of Hashem’s ways of doing this.
The other side is mentioned not only in the Torah (Ezekiel is one), but also throughout the commentaries time and time again.