Agree, but I’m thinking maybe the literal end of the first world was the Yami Yami being used to turn everything to nothingness. The second world poem does start with “a breath within the void”. Was the first world a dark void after the Yami Yami destroyed it.
And with the power of the earth(quake) as well.
Might be Blackbeard has chosen those two DFs very specifically.
Also new theory, the first world being destroyed is not symbolic, that world was actually destroyed and reduced the void of space and darkness, humanity fled to the second (current) world in arks like the Noah and the Maxim, using the precursor mother flame.