What Heidegger is saying in your excerpt is that in ancient times, it seems that people widely believed in a kind of unseen, parallel world of spirits, which Plato was using as a basis for his ideas, as opposed to wholly inventing his philosophy entirely on his own, without any precedent.

He is pointing out that Plato's metaphysics can be seen as inspired by, developed off of the foundation of earlier metaphysics, as opposed to Plato just wholly inventing them out of nothing.

When Heidegger gave that lecture, Europeans had very recently actually discovered or deciphered/translated actual empirical, physical evidence for the worldview or metaphysics of many peoples and cultures outside of Europe/The Mediterranean Coast or within that region going back further than Socrates.

They were fairly early into discovering and beginning to translate and understand much of what we, nearly 100 years later, now have widespread access to. Archaeology was still a young field at this time.

The lecture you are quoting was given in 1935 in German, and not even translated into English until 1959!

Heidegger was trying to connect what were at his time, newly discovered dots, toward tracing out the development of various forms of human metaphysics.

Heidegger is not saying that our modern concept of metaphysics is identical to those of shamans thousands of years ago.

He is instead tracing... the history... of widely varying, changing and differing metaphysical theories and ideas, either provably held or postulated to be held by many different groups of people over large time scales.

The entire point is that metaphysical theories change over time.

'Metaphysics' is not a single theory, any more than 'Biology' or 'Astronomy' is a single theory.

Those are all container terms which describe bodies of knowledge and thought within specific parameters, and they've all developed over time and place.

Plato has his metaphysical theories, as does Aristotle, and Kant, Leibniz, Hume, and these Perennial Shamans are proposed to as well. They are not all the same ideas and they are often in conflict with one another.

Anyway...

If John Woo Woo shows up in shamanic garb and you find this more convincing that him not being in shamanic garb, I would take the post modernist approach and just tell you that you find this more convincing because you have been conditioned by modern media to associate ancient shamans with purity, innocence, righteousness, spirituality and wisdom.

Also thats basically the most textbook, case-closed instance of cultural appropriation I've ever heard: John Woo Woo is dressing up in another culture's dress and adopting their mannerisms despite not being from or substantially connected to that culture, and he is doing so purely as a marketing technique to sell you useless bullshit within his own internalized capitalist paradigm.

If the commercial on TV has an actor wearing a doctor's outfit, does this imply the untested supplement you are being sold has any actual medically beneficial effects whatsoever?

Or did you just fall for a marketing gimmick?

In closing: There's science, and psuedo-science, ie, charlatans adopting some of the garb or mannerisms or vocabulary of science, but which does not actually follow the core concepts of empirical testing, falsifiability, often directly contradicts actual known science, and generally acts as a wolf in sheeps clothing, for personal profit.

To close this with what I was originally going to open this with:

It is not that healing crystals might work because the LHC has yet to discover how they work.

It is that many, many empirical, scientific studies, published and peer reviewed, have repeatedly and unequivocally found that they do not work, that they have no effect beyond placebo.