The clues: In the Kangaroo's video montage, they make multiple references to being a "survivor." They also mention that after losing someone close to them, they found themselves in the spotlight for "all the wrong reasons." There is also a random shot of a gramophone, which could be a reference to a Grammy.
Who it might be: Based on the clues, many believe the person under the mask is Jordyn Woods. The loss of a loved one could be a reference to her father's death in 2017, while the spotlight clue could allude to her drama with the Kardashian family last year. Woods made her acting debut on Grown-ish last Summer, though it's unclear if she can sing.