There are weird changes in the history of superhero comics (be it costumes or personalities or whatever) that didn't last long and are never brought up again. But that was the status during the period in which a classic crossover story or whatever was written, so generations of readers are only familiar with all that because of this one other story.
One example is how Death of Superman happened during the "Superman is the only Kryptonian" period, so we got the pink blob Matrix shapeshifter Supergirl who was in a relationship with Lex Luthor, who was in a cloned body with hair pretending to be his own son. Another typical example is when a literally who is important in an old event because they were getting pushed at the time, but now nobody remembers them from anything other than that event.