I think the older fandom would stay intact. As for the little kiddos that watch this, I think they might forget and move on. Later in life they will see FIM stuff on the internet and be like "Oh I remember watching that! I never knew it got canceled!" Then they will be sucked into the fandom once again. Because you can never leave. Nah. I don't know what would happen. The fandom would probably just diminish a bit but there would still be active people. This is just what I think, though.