I am sorry, Mia. As to why... I think ... I donno, but She had sent John back, I mean, he was no longer aware that Gigi and all of this existed. It was as if he had never met you - I think Gigi did it to spare you pain, or something.
I donno, and I think you asked Her to do it, because She told us not to tell you about him after She altered your memories.