That was a (relatively recent) retcon intended to make sense of Hawkman's continuity and history.
Well the "love story" doesn't actually stretch to Thanagar. The GA/Current version of Hawkman's connection to Thanagar arent that tight.
Nah, but it totally could.
The JSA stuff is so inside-baseball it's ridiculous. It's Prince Khufu,
and Nabu,
and Teth-Adam,
and some Thanagarian? Because Egypt? A tiny place without much history. All the important Egyptians lived in the same ten year timespan. Not that it's a bad story per se, I liked it, but it's continuity porn.
They did do some of the reincarnating stuff in Hawkman's fourth attempt at a ongoing, though. I phased out of comics around this time, so I can't say how entertaining this was. Possibly somewhat? Geoff Johns can't write emotions (that's what's called irony), but James Robinson could at the time, even if his dialogue was the verbal equivalent of Billy walking home from school, and Rags Morales drew some of it, so it was probably okay?
But then I came back, and that's when it gets
weird. Also, just abjectly bad, as
The Rann-Thanagar War is an awful, awful book.
Looking at the Wikipedia article, it's kind of hilarious how cisgendered Hawkman is through the whole thing. Why would Khufu come back as a girl? That's not how reincarnation works!
