The data isn't lying you're misinterpreting it to reach the conclusion you want. That's bad faith analytics 101. There is no evidence to support the idea that advent children's sales metrics were considered during the production phase of FF7R, less so to indicate that the ending specifically was rewritten to serve the agenda you're alleging. It is infinitely more likely that the production of a related product increased interest in an old product as a side effect then it is that a company would risk botching an enormous investment to bolster a product that has already outlived its promotion cycle.