We have reasonably shown that it is physically possible to account for the Pleistocene nonconformity in terms of ordinary dynamics over a wide range of likely initial impact conditions. We have also shown that it would be convenient if the crust had moved as described. And the mechanism used permits the survival of life even in some of the most affected areas. The bulk of the population in the highlands certainly had the best chance. However, the only surviving remnants of any projected antediluvian antique civilization(s) on the coastal plains would be those living in outposts in the highlands and those at sea.
There is some cultural evidence that there was at least some partial survival of the antediluvian knowledge base. This has shown up in the suggestive global placement of pyramids and sacred sites (the pyramids were built much later) apparently dating from shortly after the collapse. Other physical evidence is probably there, but has likely been misdated, misinterpreted and more critically, ignored.
There is also some doubtful cultural evidence that technical capability may have been far more advanced than seems reasonable within the context of the available mathematica. Empirical methods could have made up for some of the difference.
What did not emerge in this putative antediluvian civilization, or during the Bronze age for that matter, was a consumer driven society, marketing innovations globally. The old lock by a few on all scholarship certainly still existed. In any event, any such survivals of the old knowledge were available in only a few locales, perhaps inspiring a recreation of some of the knowledge base. And as civilizations rose and fell these remainders were subsumed or washed away by growing alien populations.
Importantly, with or without a crustal shift, 3000 years of rising sea levels shifted and disrupted any putative antique civilizations and sent the populations out into new lands with all the conflict that entails. The out of Eden myth has a lot going for it. This out migration notably failed to impact Australia which supports the argument for a far lower technological level than the more optimistic commentators have suggested.
I think that the balance of probabilities support the existence of a large antique civilization representing many thousands of years of human history, not too unlike the Mayan, but much more stable, that had a healthy seaborne trade and a solid labor-intensive tropical agricultural toolkit. The sea overwhelmed this civilization, but it still may have had the time (even centuries) that was needed to evacuate thousands of emigrants to new locales at substantial distances from this homeland. This is why we even have a cultural memory of the event. It could also be that this movement only took place after the second rise of the sea about nine thousand years ago.
We have a likely history of movement, the bulk of which is submerged by the second rise in sea levels. One clear argument for the complete obliteration of the original population is the slow reemergence of any form of civilization in the aftermath. Had they had three thousand years to adjust, it seems that retention of city life would have been possible in numerous locales, not least in South East Asia. After all we have ancient Bronze Age cities today in Java, to say nothing of the Indian and Chinese plains. It is possible that we simply have not found more ancient cities yet. We certainly need to dig much deeper and more broadly just to be sure
What is important to remember is that there is no special need to rely on anything prior to the Pleistocene event for a single innovation, necessary to the civilization that has since arose during the past 10,000 years. It is romantic to think that there was more influence. At the best the idea of plant husbandry came through and was recreated locally with some real prior skill. The singular lack of ten thousand-year-old inscriptions in graves anywhere in the world bodes poorly for any survival of a previous cadre of scholar priests.