Before 你 read this, the 文章 你 are about to read was from another club and has been renamed. This is considered a theory. This is also non-canon. Ok the ending would be this. This is years into the future. Ash is either married to Misty 或者 Dawn (way 更多 likely Misty) and haves a daughter. Ash is not in the video (link below).
Well the Dawn thing would make no sense so I will explain.
In the beginning of the video, on your right is future Misty. On your left is future Dawn (possibly). And the middle is Ash's daughter. Well if 你 are still confused about the Dawn thing 你 can see that on your right in the video it's a woman in blue hair. It's obviously Dawn (likely).