Here you present a hypothetical (people are are getting called racist for [respectfully] suggesting that students should stop listening to some explicit forms of rap music) while asking me for concrete examples. When has a person been called racist for such a thing? Can I ask you to stop with your double standards?
And Again you are only looking at it from your (privileged) perspective. What if the only "positive" imagery you could relate to was not so positive. You would still have little choice but to relate that imagery for self esteem. And what if somebody from another group who has the privilege of an abundance of relatable alternative positive imagery came and told you not to relate to that single source of positive imagery available to you. Until race becomes a non-issue (I don't see that happening anytime soon) one thing that you can do to help is support alternative positive imagery for minorities. Find a minority politician (Ocasio-Cortez maybe?) you like and support her... have a James Baldwin meetup. Tell people the truth about Christopher Columbus and how sophisticated the people who were subject to his genocide were. Spread positive image about people other than whites and you will surely start solving the problem. Being the angry white guy that keeps saying "Stop listening rap music" is probably not going to work.
Please note that there is nothing wrong with spreading positive messages about whites, but ensure that you are not doing so at the expense of the truth or at the expense or exclusion of other groups. This is root cause of the problem and the article does not even touch upon it!
* And yes there are positive role-models in the African American community but not enough to counter the overwhelmingly biased media.