Seems to be a cosmetic issue only?
It’s a shame if you mention anything about possible negative effects of fluoride you get lumped in with the crazies.
(just to be clear I am a rational science freak, but my kids have higher priority and we know scientists and corporations have messed up more than once, not going into 'just trust us' with literal poison just because it has good side effects on teeth)
Only at low levels: “Moderate and severe forms of dental fluorosis, which are far less common, cause more extensive enamel changes. In the rare, severe form, pits may form in the teeth.”