I would think someone who has experienced an NDE would interpret it in the context of whatever spiritual beliefs they already held.
This is true. It's true of any experience we have in life. We always interpret it within our current framework of reality we are operating within as the norm. But what distinguishes NDE as an experience is that it is far beyond the norm, so it takes on archetypal symbols and forms as the face of what was experienced. This is why typically in state-experiences like these, they will often take on those symbols on this level of the culture which uses them. It's less likely a Christian will see a thousand armed Bodhisattva than they will Jesus or Mary or an angel.
But here's the salient point, they are in fact experiencing something real. The face of it is not consistent, but then neither is the face or interpretation of what we call 'normal' reality. Each person is unique and interprets these things through typical conventional structures, but they are not, nor ever 100% identical. What we call "reality" is really nothing more than a shared common language where we are at best close in approximation to each other in how we interpret these things.
Though NDEs will vary in interpretation, the fact remains they all are experiencing something life-altering. The experience is so powerful it goes beyond the experiences of mere hallucinations, which some without any experience on these level attempt to label them out of convenience. They are not hallucinations. But they also do not prove that what is experienced within them are actual, literal objects in the universe the way we might experience a dog or a cat or another person. They are very real, but the mind fills in the blank with something that both conveys what it sees 'beyond' them, while allowing the mind to reach towards it from where it is at presently. This is how symbols function.
It would be interesting to know how many NDE's were conversion events. I know one woman who had been agnostic and experienced an NDE. She subsequently converted to Christianity and attributed the NDE for her change of heart, although she never claimed to have seen Jesus. She converted with little investigation into other faiths, so far as I could tell. She had been raised in a Christian home.
Sounds similar to myself. I sought out religion following my own experience in order to provide some context of understanding it for myself, in order to explore what had opened to me, to unite with That again as it went deeper into myself than anything we can normally fathom. And no, it was not a hallucination. Those operate in a very different way, and are notably different experiences. They are far more from the primal subconscious, rather than archetypal or transpersonal in nature.
I subsequently pursued the Christian faith in order to know "God", which was how I experienced that with white light, life-review, infinite mind and presence, etc. (it's very personal so I won't go beyond a brief description here). What I found over time as I pursued knowledge within it is that the interpretation of these symbols within the religion by those who had no direct experience of "God" on this level, were expressions of their speculations and mental models of God based upon whatever their normal personal and cultural experiences they had were. A God who sent people who didn't believe like them to hell, for instance, had zero referent in my experience. In fact it completely violated the nature of what my direct experience was on the core level, not just simply a different 'face' of the same sort of experience as you might expect from someone of a different culture.
The point is, it does not prove ones particular religion's symbols are actual, literal persons or beings as described by their religion. It proves that we all have an experience of the same thing that is well-beyond the "norm", one that is not a hallucination, but described as "real reality" by those who experience it. How the mind subsequently interprets the direct experience, is just that. How the mind interprets it. How literal, or abstract that will be is entirely based on where someone is at developmentally. Someone with no experience themselves speculating about it from the outside, say as a so-called skeptic, or as someone who wants to make these prove their particular religion is true, are doing so without the benefit of actual experience.