If the 'soul' is a hypothesis, as opposed to wishful or magical thinking, then you should be able to explain what characteristics it has and what methods could be used to test for its presence (or absence, where said asserted characteristics are absent) - but it seems 'soul' proponents can't get beyond wishful or magical thinking.
Therefore 'soul' is not a valid hypothesis: it is an invalid hypothesis that no unbiased academic researcher would take seriously in the absence of robust methods to investigate the claim. If I think back, having done a research-based higher degree (Ph.D, University of Edinburgh, 1995), had I used the word 'hypothesis' in the same way that you have here I'm pretty sure the Prof and my two supervisors would have chased me out of the room and told me not to come back until I understood the term properly.
As regards these 'NDE's', I surprised that you're still banging that drum: you've mentioned the likes of Raymond Moody before yet his 'work' isn't something I'd ever want to cite, since it is so embarrasingly flawed.