I think I assign close to zero probability to the first hypothesis. Brains are not that fast at thinking, and while sometimes your system 1 can make snap judgements, brains don’t reevaluate huge piles of evidence in milliseconds. These kinds of things take time, and that means if you are dying, you will die before you get to finish your life review.
My guess is that our main crux lies somewhere around here. If I’d thought the life review experience involved tons and tons of “thinking”, or otherwise some form of active cognitive processing, I would also give ~zero probability to the first hypothesis.
However, my understanding of the life review experience is that it’s the phenomenological correlate of stopping a bunch of the active cognitive processing we employ to dissociate. In order to “unsee” something (i.e., dissociate from it), you still have to see it enough to recognize that it’s something you’re supposed to unsee, and then perform the actual work of “unseeing”. What I’m proposing is that all the work that goes into “unseeing” halts during a life review, and all the stuff that would originally have gotten seen-enough-to-get-unseen now just gets seen directly, experienced in a decentralized and massively parallel fashion.
This is related to the hypothesis I’d mentioned in the original post about attention being a filter, rather than a spotlight. On this view, we filter stuff out to help us survive, but this filtration process actually takes more energy than directly experiencing everything unfiltered. This would counterintuitively imply that having high precision on (/ paying attention to) a bajillion things at once might actually require less cognitive effort than our default moment-to-moment experience, and the reason this doesn’t happen by default is because we can’t navigate reality well enough to survive in this lower-cognitive-effort state.
I think we’d still need an explanation for how the memo to stop dissociating could propagate throughout one’s whole belief network so quickly. But I can pretty easily imagine non-mysterious explanations for this, e.g. something analogous to a mother’s belief network near-instantaneously getting the memo to put ~100% of their psychological and physiological effort into lifting a car off of their child. The Experience of Dying From Falls by Noyes and Kletti (sci-hub link here) describes somewhat similar experiences occurring during falls on the top of page 4.
I should also mention that on my current models, just because someone experiences a dump of all their undissociated experiences doesn’t mean that they’ll remember any of it, or that any more than a tiny minority of these undissociated experiences will have a meaningful impact on how they’ll live their lives afterward. I think it can be a lot like having a “life-changing peak experience” at a workshop and then life continuing as usual upon return.
Isn’t the more analogous argument “If I’m thinking about how to pick up tofu with a fork, and it feels good when I imagine doing that, then when I analogize to picking up feta with a fork, it would also feel good when I imagine that”? This does seem valid to me, and also seems more analogous to the argument you’d compared the counter-to-common-sense second argument with: