The Behavioural Science Unit probably has a name for claims like this.

@Background Pony #1D9F  

 
That….and the fact that there’s no official flash model for Wallflower in pony form, unlike Sunset. So there’s that.

But doing anything more than adding assets they already had would take effort, and we can’t well have that can we?

@superfun  
Except most of the comics are not canon to the show.

Would have been cool to see a canon Wallflower pone to be honest.

Wallflower’s pony form WAS in the comics, but Twilight wasn’t among the group who saw her.

@Setsugekka  
because OP needs reasons to be upset so they can fill their status quo for the day

None of them ever meet or saw Wallflower, so how could they possibly remember her?

@Twiface  
because Sunset has a pony form/design readily available and Princess Twilight has no idea who Wallflower is
 

@Twiface  
True but she was also shown as a pony character whereas I don’t recall ever seeing Wallflower as one.

@Background Pony #7AF0  
I don’t know, but they included Sunset Shimmer anyway

Why would an Equestria girls character be in a different series?