Something doesn't add up regarding the connection between Amdapor and Norvrandt...

[Iscah]

That interview was made in March 2017, 3.5 had launched in January 2017 and 4.0 launched in June. I'm going to make the assumption they had started to really pinned down what Astral/Umbral and what Light/Darkness were by that moment since they were already planning for the next expantion.

I really think the revelation we got from Urianger is that Astral and Umbral should now be distinguished from Light and Darkness. What was confusing me (and what i feel confuse a lot of player atm) is I made the relation Astral=Light and Umbral=Darkness since ARR and nothing made that assumption false up to that point. The explanation is pretty clear thought:
1) There's no umbral or astral energies, it's only a state of how one element or a mix of element manifest;
2) Darkness and Light are true energies, not elements;
3) Darkness and Light are not the same thing as Astral and Umbral; (But we now know they can have Umbral/Astral charges)

I'm not saying that umbral and astral are "energies". They're polarities or aspects which can apply to any of the elements.

And while Eorzea uses those terms, they are labeled differently on the First.

The active polarity is named "astral" in Eorzea and "Darkness" in Norvrant.

The passive polarity is named "umbral" and "Light".

Meanwhile, separate to the Dark (active) polarity and Light (passive) polarity, there is Dark energy and Light energy. They're separate concepts using the same terms.