Or, more accurately, people who are religious interpret the experience according to their religious vernacular. Christians see the Christian God, Muslims see Allah or Mohammed, etc. The parsimonious interpretation of this phenomenon is that people already predisposed to religious interpretations of events apply that interpretation to these profound and rarely-encountered mental and emotional conditions.
You've attempted to resolve this problem by saying that everyone's religion is valid and all models of heaven actually exist. Sadly you can't seem to reconcile this with atheism, nor can you describe how subjective belief results in physical reality. As such your explanation is not very parsimonious. It leaves too many questions you can't answer.