So, to make a long story short:
TWI: She rules Equestria.
AJ: She’s an aunt of one. Inherited Sweet Apple Acres after Granny’s passing.
DASHIE: Chief of the Wonderbolts
PONKA: Married or couple to Cheese. Has a daughter.
RARARA: Left her boutique to Yona and Sandbar?
SHY: Still with her animals. Probably Discord’s official fiancée?
LYRA AND BON BON: They married.
THE CMC: Teachers at the Friendship School.
GLIM GLAM: Principal of the Friendship School along with Sunburst. They probably have a daughter?
DERPY: She’s leaves her job as a mailmare and she’s a successful enrepeneur. Muffins, of course.
DOCTOR: Roseluck’s couple
YONA: She has grown a lot and settled in Ponyville to live with her horsbando: Sandbar.
SPIKE: I’ve left him for last. He’s a buff, handsome dragon. Is he Equestria’s Chancellor? Has a relationship with Rarara?