Hmm thought it might be TCW. They haven’t brought in old EU characters yet and I’m starting to wonder if they ever will.
There have been a couple more Thrawn hints lately. Dave Filoni posted a photo of the SW logo on the spine of a Legends book that some claim to have identified as Heir to the Empire with a caption that included “Remember, there’s always some truth in legends” in reference to an upcoming Rebels season 3 panel, and there’s a blue guy in a white uniform on the Where’s Waldo-style Celebration poster (which would seem pretty meaningless, but there are no other obvious Legends references, so it might be important). I think the most obvious lead we have right now was the fleet admiral from Aftermath, so hopefully we get some kind of resolution when Life Debt comes out next month.