Many, many years ago I was asked to implement a filter like that for usernames. I said right away that it wasn't going to work well, but I did implement it.
Next internal build, the CEO can't create an account. With his real name.
It worked exactly to spec; I added a debug print and showed everyone the "bad word" it tripped on. The idea was promptly rethought.
Now I'm trying to figure out which word that would be, but yeah.
That reminds me of a bug I fixed where my bosses boss found it, we did everything, my boss at the time forced us to deploy anything and call it fixed. Then someone else saw it half a year later, I finally figured out the root cause and fixed it (localStorage vs sessionStorage) and my boss was acting like he didn't know what I was talking about, but I could hear it in his voice. I didn't press too hard, I just pushed the real fix out. It was basically a "client-side" bug of a gift card balance saved in localStorage that never updated, so I changed it to sessionStorage. Not quite the CEO, but the guy below the CIO finding a bug can worry just about anyone.
In my case, the regex would have been for a friend to filter reddit or discord slurs, so not as awful.
Two of my co-workers have the last names Dyck and Cox. I've seen others whose last name is literally Dick. And let's not forget the famous actor Dick Van Dyke who strikes out twice on most filters. I've heard several other names from other ethnicities that were straight up "slurs" by some people's standards. The only thing harder than matching a slur is deciding what words count as slurs.
Next internal build, the CEO can't create an account. With his real name.
It worked exactly to spec; I added a debug print and showed everyone the "bad word" it tripped on. The idea was promptly rethought.
I feel like the AI did you a favour here.