I wish I could say it's surprising that a tech company launched a product like this without an established process to replace accidental use of derogatory words or slurs, but it's not. I can understand how it happens -- maybe they used a semi-automated process for building the word list and it included things that were considered "safe" 10-20-30 years ago. But once somebody informs them of their oversight, to continue just blithely using a word that (as I understand it) is widely accepted to be an offensive slur... that's just wrong.
You built your software in such a way that replacing a "bad" word is technically challenging? Well, that was dumb, I guess you need to spend your time and treasure fixing it the hard way, because you can't just ignore it and hope it goes away. If nothing else, the fact that one such word got through the process strongly suggests that there will be others in the future.