Are "Undetermined Role (uncredited)" entries valid?

I noticed that on the page for Kesha (I), a well-known singer, there is an actress credit in the movie Dreamgirls (2006), but her role is listed as "Undetermined Role (uncredited)".

As I understand the rules for uncredited work, when someone appears uncredited in a production, the person's "character name should include a description of the part - Woman with Dog, for instance. ... It's not enough to have just worked on a production: The scenes must be included in the final cut, and it must be possible to easily identify their appearance."

https://help.imdb.com/article/contribution/filmography-credits/cast-acting-credits-guidelines/GH3JZC74FVYKKFMD#uncredited

In light of this, how can an uncredited role be accepted with the character name "Undetermined Role" be accepted, particularly for a famous person? If Kesha really is in the movie Dreamgirls, presumably someone should have watched the movie, found her appearance, and given a proper description of her role so that others could look for her in the movie. But if nobody has been able to find her appearance in the movie, how can we be sure that Kesha really made the final cut? 

Even if she were known to have worked as an extra during the filming (I don't know that she did; this is speculation), there is no guarantee that any scenes showing her would have made it into the movie.

So I would like to know if "Undetermined Role (uncredited)" entries are really eligible for listing or not.