If Hub wants the fandom to survive, they'll have to make it up for them.
If they do, they'll probably have two choices.
1.) Death/Sickness of the remaining 5, due to a new villain, Twilight's sacrifice
to revive the 5, and remains a normal unicorn pony.
2.) The 5 leaving and separating. Each of the episodes show their
experiences outside Ponyville. Towards the end of the season, it will
show a villain and how the 6 must be together to defeat him/her, and
eventually remain together, and Twilight rules a region of Equestria and makes
Ponyville the capital and all that stuff.
great plot huh? ;3