Well, the aesops still work, even if
they haven't completely learned their lesson yet. It's not unusual for the target of an aesop to completely miss the point, either — particularly when it's something they're so passionate about.
Plus, I wouldn't be surprised if Diamond Tiara and Silver Spoon are keeping up their nasty bullying ways, even if we haven't been 'treated' to witnessing more of it yet. After all, the two
Spoiled Brats got upstaged at their own party. That's not exactly going to convince them to back off; if anything, I'd expect it's made them
worse. Even more determined to prove that they're "still superior to those
Blank Flanks." So there's a potential stressor driving them to keep trying.
I'm actually sort of disappointed that we haven't seen Twist really show up outside of background shots since "Call of the Cutie". She seemed to be friends with Apple Bloom; I hope she hasn't become so focused on earning her mark that she neglects her friendship just because Twist already has hers. It already seems likely that unless the girls all earn their marks at the same time — which seems rather unlikely — that there's going to be a bit of a rift once one of them gets theirs first. Maybe Twist will turn out to be a
Chekhov's Gunmare then and show up to help the odd filly out cope with the sudden rejection/jealousy?
Also, I found it interesting that Sweetie Belle balked at writing their song or the thought of being the lead singer. Being shy about it like she said made some sense; just because she was willing to sing along with her friends doesn't mean she has the confidence to sing
solo in front of such a large audience. She was willing to show off to Fluttershy, and the other fillies' reactions showed they'd already heard her singing before, but that was in the privacy of Fluttershy's home. But in front of a bunch of strangers...?