It's called being a hypocrite at the expense of someone else.
Sounds the same as biased historical narratives by mainstream social factions. Such as Texas Republicans seeking to sneak textbooks into high schools that refer to enslaved Africa as
migrant workers. Just the same, based on what I read from various sources, I wouldn't claim your assessment of cancel culture is inherently wrong. I see that it is sometimes equated with Call-out culture, which I think isn't the same thing, despite some claims to the contrary. I see it as an effort to remove false narratives and replace them with the truth.
Let me give you an example of my take on call-out culture. A take which I admit pisses off minorities, and is just as unpopular among whites. Removal of confederate statues, I don't mind them remaining as long as they share the space with relevant/related statues exhibiting the contributions of the exploits of Black soldiers and regiments. Doing so advocates a
whole narrative rather than a biased one-sided account. For example, Harriet Tubman did more than just operate the Underground Railroad, she was a
noted military leader. Yet history textbooks ignore this side of American History. Call-out culture would seek to make sure such accounts are included in what's taught in our schools, as opposed to ignoring and/or marginalizing the Black part of American History. A statue of her, sharing the one along a relevant/related confederate statue, I could easily advocate.
Truth is hated unless it either flatters one, or denigrates others.