At one point in the "Obi-Wan Kenobi" trailer, we see the Grand Inquisitor facing someone who has their back turned away from the camera. A lot of fans theorize the silhouette belongs to none other than "The Book of Boba Fett" actor Temuera Morrison and he could be portraying a clone trooper like Captain Rex or Commander Cody, who are clones of Boba Fett's father, Jango Fett. One fan did a side-by-side comparison of the mystery person's silhouette with that of Morrison's, and there's no denying they look similar.
Image Source: YouTube user Star Wars