Q. Is the world experienced in a near death type experience technically real?
A. It depends on the definition of reality!
For example, the floor beneath you is considered real. Why? Because it is a consistent aspect of your experience that fits neatly with other experiences (for example, many objects can be placed on and moved about on the floor) and the experience of the floor is confirmed by others. If the floor is sometimes present, but sometimes seem to disappear, we would not say it is real! Or if a vast majority of people said that we are not on a floor but on some other kind of surface, or even not on a surface, the general opinion would be that the floor is not real.
This should not be used as an excuse to deny the importance of relative realities. Yes, we live in a relative world. However, within that world, there are things we place importance on as a society. We can, of course, question these, but stating that they are relative and therefore not real denies the very experience of living together in a society. That is not what I am suggesting by inquiring into what is real.
When there is an experience in which the entire set of priors disappears and an entirely new foundation of space, time, identity, and relationships appears, there is little underlying common ground to discern what is real and not real – just like in a dream, when, within the dream, the dream is real. The dream is only unreal when we change our state of consciousness to the waking state. The waking state contradicts the apparent reality of the dreaming state. The dreaming state contradicts the apparent reality of any other state.
Similarly, a near death experience, or mystical experience, or dreaming experience, has its own reality. What matters most is being able to navigate these realities without being overwhelmed or confused.