Rumors are flying that both Thrawn and another popular animated canonical Star Wars characters might have actually been cast to appear in several upcoming series already. Sites such as LRM online confidently claims that both Thrawn and Ezra Bridger will be played by Lars Mikkelsen and Mena Massoud respectively.
Mikkelson previously voiced Thrawn on Star Wars: Rebels. Massoud was the main starin the live aciton adaptation of Aladdin and also photo on Instagram captioned with a quote Bridger says in Star Wars: Rebels.
Now these are just rumors so keep that in mind. We will keep you posted as more information is released.