"Having 2 heroines, Aerith and Tifa, and having the hero waver between them, that was something new."
Ehh, I think it'd be best to change the way most people understand this quote. The context here was Kitase talking about the scenario, and if we're really saying "the hero = Cloud"—it's just, literally not the actual scenario in the game for the character. Like, as to the word "literal" as I can mean—it isn't expressed from the character or is a plot point at all of Cloud having some conflict of "Aerith or Tifa? Can't decide". Just didn't happen.
Versus, if "the hero = player", in vein of what Kitase meant, then that can actually have something to stand on to make sense. In that, this was the first scenario where the player could have choice/favor between two heroines and have all these choices that give different reactions/rewards—no FF game did this before 7 at that time. Any player could literally in their experience waver between the two and that would impact their individual gameplay, but as an aside to the strict story.
I'd rather go with the latter perspective because it's the only one that makes sense, I'd say.