"I'm looking forward to the future, and feeling grateful for the past." -Mike Rowe
When MLP: FIM does end, while I'll be sad its over, I will be happy that the show has done so much. It turned something that was considered a lame property by so many and turned it into a cultural phenomenon. I'm also happy that it raised the bar for the franchise, as from what Ive heard, the Gen 5 creators and writers have said they know the fans are what make it great, and intend to build on it for the next series, they are aiming for a much older audience(No not talking anything like TV-14 or M or anything silly, I'm talking TV-Y7-FV) and are using Toon Boom Harmony(an upgrade from Flash Animation, side note they also worked on the MLP movie) I can also say, with relief and happiness that the 2020 series will NOT be in CGI(the animated movie prequel will be, but the series will be 2D, and done by Toon Boom).
I'm happy My Little Pony: Friendship is Magic lasted so long and from the email, they intend to leave no lose ends untied and make sure its not open ended. In the words of RebelTaxi., was it cancelled too soon, was their a story left undeveloped? No, My Little Pony had 221 Episodes, 9 Seasons, a spin off series and a movie(For theaters!)
I'd rather have the series end on a high note like Star Trek: The Next Generation rather then continue and rot like Fairly Odd Parents.