The fandoms most milked non-joke

@HamburgerTime  
They are hinted to be the ponies in the “Equestrian Gothic” photo in Season 3 Episode 8. Also Applejack stares into the sky as two shooting stars pass by right after Granny Smith says that they have the “whole” family together this time implying that her parents are no longer around to attend. Sabby has admitted to incorporating those stars for that exact reason. Applejack’s parents are dead and it is cannon. (If you consider the entire project staff’s incorporation including the animators.)

@(T_a)  
Fluttershy’s parents have not been mentioned, shown, or hinted upon. They may or may not exist.
 
I headcanon that she’s either an orphan or from a broken family, but that’s just me.

@(T_a)  
They are joint-captains of a rival flight team to the Wonderbolts. They wanted Fluttershy to become the leader after they step down, but when she gained her cutie mark and lost all interest in flying, they disowned her.
 
She moved into her earth-based home mere days later, with the vow that she’d never treat an animal the same way her parents treated her.

@(T_a)  
Fluttershy’s parents disowned her, and then flew away to space.

I just realized something…I have never seen fluttershy’s parents
 
Or they did show them, and I’m just completely oblivious