Jo didn't so much get an invitation as much as told by her best'ies she was expected at the Hallowe'en Feast. There are several reasons this is awesome.

She gets her first Hogwart's Feast since graduating. She gets to toss confetti in Lee's hair. To run into all those Professor's that still remember some of her more glorious exploits.





(And if she happens to glance over Ozai or Steph or her Order Members now and then, while scanning the hall and laughing at the antics of all the wee adorable children's? Well, that's just a coincidence.)