My daughter just told me, "If you really stretch it, you can make what you post on social media true."
Alas, I must concede the point: upon actual cursory research, drinking distilled water is NOT a health risk.
(I was once admitted to hospital because of crazy electrolyte levels, while presenting other symptoms as well. Is long story. Perhaps it's time for me to stop worrying about potassium...)
Its not just a US thing, other places in the world have fluoride in their water. In many areas fluoride just naturally occurs in the water at levels even higher than what managed services target. But other countries, such as Hong Kong, parts of Malaysia, Singapore, Ireland, parts of Spain, parts of the UK, parts of Canada, Mexico fluoridates table salt, most of Austrailia, Fiji is rolling out a program, half of New Zealand, about half of Brazil, and most of Chile all have some water fluoridation programs. Many other countries did at some other point in time but stopped doing it.
Also potentially dangerous.
If you drink a gallon of distilled water all at once, it could screw up electrolyte balance. Screwy potassium levels can cause heart fibrillation.
I would guess that the risk of water that's coming from reverse osmosis is safe for routine use, in the context of a healthy diet.