I know very little about Kate Middleton, William, Harry or Meghan & really care even less. Maybe you're right about her, but if you are that article failed to make the case. E.g. the claim that Middleton wept in order to sabotage Meghan's wedding is based entirely on interpretation, absent concrete documentation. Similarly her alleged influence on palace social media standards seems like pure speculation.
Also, I wouldn't assume it's only white people who believe that celebrating a young woman's cancer diagnosis violates Medium's editorial standards.