It sounds simple but data conditioning like that is how you get scunthorpe being blacklisted, and the effects on the model even if perfectly executed are unpredictable. It could get into issues of “race blindness”, where the model has no idea these words are bad and as a result is incapable of accommodating humans when the topic comes up. Suppose in 5 years there’s a therapist AI (not ideal but mental health is horribly understaffed and most people can’t afford a PhD therapist) that gets a client who is upset because they were called a f**got at school, it would have none of the cultural context that would be required to help.
Techniques like “constitutional AI” and RLHF developed after the foundation models really are the best approach for these, as they allow you to get an unbiased view of a very biased culture, then shape the model’s attitudes towards that afterwards.