The new hero is going to be Rey. Their 'State of the Galaxy' post stated that "Our first character from SW:TLJ will be making an appearance before the movie comes out in December. This is going to be a variant of a character that fans of SW are already familiar with, so stay tuned for more details."
That is the exact quote. Rey recently got her named changed to Scavenger Rey, a variation of Rey. No other heroes from that SW era have had their names adjusted at all, or have a built-in variation name.
Rey is a hero everyone is familiar with. Most likely going to be her. Of course, they could add 'Kylo Ren facial scar', 'Captain Phasma post garbage compactor', 'Poe in pilot suit', or even 'Finn in sleeper pod'. All of those could be variations.
But, Rey got updated. She's the new face for SW. They just had the BB8 event with Rey, Finn, BB8, and Smugglers. I'm thinking they're going to pull a mix of the Thrawn and CLS events. Release Smugglers to farm a week before (Phoenix for Thrawn) and require BB8 (R2 for CLS) to unlock the new Rey. Just seems like CG 101 right there.