The fact Jigoku-hen uses the events of Mobile Suit Gundam: Char's Counterattack means Char Aznable has gone against his previously established word of ensuring the "Black History" will not happen on his watch. Players had already declared him a Hypocrite and a liar, except that's exactly what Char is in Char's Counterattack (he lies about not Colony Dropping any more asteroids after The Federation hands him "Axis", but he does it, regardless).
Though it likely deals with the memory muckery that has affected all of "ZEUTH" and "ZEXIS" during the game.
As it turns out, Char really DID keep his word in the end: he was using "NeoZeon" for his own goals of helping "Z-BLUE".
Wayne Ribtail and his willingness to attack female pilots isn't a case of misogyny: because Wayne's a feminist, he would treat a woman on the battlefield no differently than he would a man, thus he wouldn't give a second thought or hesitate striking a woman, when the core principles of feminism is "equal opportunities for women".
The Leitmotif for Australis, "Delusional God of War", is a somber remix of "Broken World's King", the Leitmotif of Gaiou. It makes sense the former sounds similar to the latter because they're both Dimensional Generals.
Fridge Logic
The Mayan prophecy's mentioned throughout Jigoku-hen: Blood of Beasts (Team D), Fellowship of Water (Aquarion), Destination of the Wind (Simon), Civilization of Fire(Newtypes) and the Brilliance of the Sun (Tetsujin-28). However, there's no Moon age despite there's so many Moon themed mech around (Zambot 3, Turn A Gundam, Gundam Double X). Also, why isn't Daitarn 3 the Brilliance of the Sun? Banjou Haran even says it as part of his catchphrase.
Z-BLUE, specifically the Celestial Being portion, already had to deal with both Al/Hal and Soma/Marie. Why didn't Celestial Being realize that Ambriel is Suzune's Split Personality?
", but recall that as the bearer of the Sphere of the "False Black Sheep", everything about him is a lie, thus his Leitmotif wouldn't fit him at all.