Correct, 1920x1080 is 1.78:1 ratio, and any wider ratios such as 2.35:1 are letterboxed within that frame, so there is no 'anamorphic' in a DVD sense for Blu-ray.
The specs do include the option of 1440x1080 which could be flagged as anamorphic, but I have yet to see any disc use this.