You guys remember this interview with Kitase?
EGM: At the very end of FFVII, we see the epilogue to the whole story that takes place 500 years later, so really, you still have another 497 years’ worth of games and movies to fill in....
Kitase : Ha, maybe I’ll try to do that. In a way, I consider that epilog to be the true happy ending of FFVII. Well, it’s a happy ending even though all the human beings are destroyed. [Laughs] - Kotaku
He’s referring to the same scene that Nomura is talking about in this quote:
Nomura: “....The shot of Midar that appears in that particular sequence was FFVII’s greener version of Midgar, 500 years in the future. It symbolizes people returning to living aboveground. (....) So it’s a story where in the end, people go back to living aboveground, choosing a life closer to nature.” - Reunion Files, pg 105