It's probably because the song held the whole thesis together. They were probably putting all their eggs in the "IT'S A THEMATIC LOVE SONG" basket, believing that a solid confirmation that it was a CA [only] song guaranteed the outcome they're preaching, but now that that's shot, word has it that some of them are on a wiki editing spree.
If this isn't a cautionary tale about making sure to hedge your bets, I don't know what is.
Anyway, regardless, I thought it was a good thing that the song actually revolved around her feeling the weight of being the last Cetra since that was supposed to be at the forefront in any case, and it should dull some of the criticism people had about perceiving Aerith's attempted advances with Cloud as entirely inappropriate given the situation with Tifa.
Also, I saw some of the posts reading back about Claudia and the infamous "older girl" line and I think that it doesn't actually have any bearing what she thinks (though she seemed to already approve of Tifa in ToTP, but that's besides the point). Not saying Cloud doesn't love his mom or care about what she thinks lol all I'm saying is that it is, again, a discussion that offloads choice from Cloud (who does end up making all his own choices, fully and consciously).
Then again, how could I forget the infamous exchange in Cloud's Aerith's Resolution:
Aerith: Don't fall in love with me.
Cloud: Doesn't my mom get a say in this?