Yeoh’s precise role is unconfirmed at this time, but her involvement comes by way of Nicholas Meyer, one of the consulting producers on Discovery. Meyer, who also helmed Star Trek II: The Wrath of Khan and Star Trek VI: The Undiscovered Country (certainly the best of the Star Trek motion pictures), dropped the news during a discussion of his 1979 sci-fi classic Time After Time.
After the news that she'd been cast in the series broke, Deadline reported that Yeoh’s role was that of a captain, but of another Starfleet ship, not of Discovery.
The series centers on a female starship captain, a role that has yet to be officially cast. The series debut was delayed from January 2017 to May 2017 (see "'Star Trek: Discovery' Delayed"), and showrunner Bryan Fuller left amid reports that series development was not proceeding quickly enough (see "New 'Star Trek' Series Loses Showrunner").
The show is currently set to debut on broadcast TV before moving to CBS’s digital platform. Because the show will air digitally, it may embrace profanity and nudity (see "'Star Trek: Discovery' May Boldly Embrace Nudity, Profanity").