Thrawn is a fascinating character. If you haven’t read Zahn’s 6 new canon novels about him, I highly recommend them. He’s easily one of my favorite Star Wars characters and I cannot wait to see him on screen in live action at some point (HT please!). I doubt he’s more than just a name or at most a shadowy reveal of his back. Ahsoka is where he’s most likely to show up given what they’ve set up. But they could still build him up a bit here before that happens.