Below are my predictions, not including base villains, and assuming 5 characters per pack.
Fates
Azura - Of course, opens for Vallan History Maps
Oboro - Most popular Hoshidan retainer, infantry lance
Arthur - Infantry axe, Nohrian retainer, jokey character (could also be Niles)
Odin - Another mage, technically double representative whammy
Selena - Same thing except another swordie, so she could potentially be an easy clone
Shadow Dragon
Navarre - Come out come out wherever you are
Minerva - She would be the game's second wyvern rider! And she would open up Macedonian History Maps
Merric - An important character, mage, etc.
Linde - The first light mage
Michalis - Villain of Macedonian History Maps
Awakening
Tharja - As if she won't be there
Virion - A character who seems to like getting into spinoffs, opens up Valmian History Maps
Cherche - The most popular Awakening girl not already in, foil to Virion and appears in Valm
Gaius - A popular boi
Walhart - Villain of Valmian History Maps