I am not who you asked but I can see an argument being made that, yes, a banned word list consisting of racial slurs is still bad, albeit significantly less so.

The argument would go something like this: you can ban use of racial slurs without specifically making a list of them that are banned, as such a list both opens the door to further banned words and also comes with a maintenance cost, where it has to be changed. As an example "person of colour" is currently an acceptable term but when I was a kid I think people would have associated that term with "coloured" and find it insulting, so if you have a specific list you have to manage cases like this.

Secondly banning racial slurs altogether ignores that there are legitimate contexts in which they should be used (directly quoting something someone has said, discussing old media in which that sort of language is used, etc.), and these contexts are very different from referring to an individual or a group using those slurs. A list of banned words means those words can't be used even in those contexts, as opposed to just not using them as a pejorative or insult.

Yes, it's unnecessary at best but potentially causes other problems. Really, if somebody uses a racial slur, does somebody above them really need a banned word list to caution or discipline them? Of course not!