Well, this is just my take but I think you got it right with it being because the dream was created inside Auxo. CJ just created a reality where everyone was happy and nobody ever knew him, since in that same arc he keeps struggling with the thought that everyone's lives would have been better without him. Since Auxo is truth, the dream morphed to represent everyone's truths. Kieran wasn't included and instead was shown what she really was. Cro took Sarah's place, and now we know why. The true connection of the Hebe shards was revealed, and CJ, who wanted a mother, called to who is his/Jacob's true mother, who is still spiritually connected to him. He doesn't know what everyone experienced because he only created "a world where they didn't meet me," or at least that's what I think after what he said in 51. And because that's all he did, he only knows what he experienced in it; he didn't put in the specific details of that dream, only that one condition + Auxo Truth's influence.