Lars Mikkelsen refuses to answer when asked about making his live-action debut as Thrawn in The Mandalorian before Ahsoka. Mikkelsen, who voiced the brilliant Imperial tactician Rebels, is reprising the fan-favorite villain. The Ahsoka trailer, which debuted at Star Wars Celebration, showed he will make his highly anticipated return in the upcoming Star Wars series.
https://screenrant.com/thrawn-the-mandalorian-ahsoka-debut-when/