Last I heard, back in '97 they did “conform” the negatives to the SEs, but they did NOT destroy the original frames they replaced. They did in fact preserve them. They simply spliced them out and spliced the new frames into the negative. That’s why it is both true that the O-neg is “conformed” to the SE and that everything is preserved.

Regardless, we know for a fact that there is nothing stopping them from restoring the originals. Not only should everything from the original negative be preserved in one form or another, but even if it wasn’t, lower generation copies certainly still exist. There really is no excuse, even if it wouldn’t be absolutely perfect. If fans here can make acceptable versions with only publicly released materials (well, until the 35mm scans anyway - but even with just the upscaled GOUT it was OK), then they certainly can make better versions with the resources at their disposal no matter what condition the original negatives are in.

Bottom line is there is zero technical excuse for them not to do it. Films that were in far, far worse shape or come from far, far weaker sources that have far, far less demand have been meticulously restored. No reason whatsoever not to do it here.