I'd argue that all of those scenes were still pretty much just concepts of what they plan might happen in the game.

So basically, it's what the writers would start with and decide on the story from there, even scrapping many of those initial concepts. Except this time, they announced it before even workshopping it. That's the crucial difference. Hence my earlier comparison - had the same thing happened to VII, people would have been upset that we didn't get that original game where it was just Cloud, Aerith and Barret, and "who the hell is this lame childhood friend chick? She's sexist as hell! This story was way better until they went and changed it"