It's always difficult to predict the future, as it depends not just on reason and science, but on what issues become viral in social media or get picked up as the "cause of the week" by celebrities or politicians.
The basic facts are that fluoridation programs in Europe and North America and other parts of the developed world have been responsible for a massive improvement in dental health among people of all economic classes. The relatively small amount of fluoride added to tap water has no known harmful side effects.
Although the same benefits can be obtained by regular brushing with fluoride-containing toothpaste or mouthwashes, achieving these benefits requires that people actively use toothpaste with fluoride on a regular basis. This means that while most middle class and wealthy people would retain good dental health without fluoride, people living in poverty or afflicted with bad arthritis or other diseases which might make regular brushing difficult, would suffer.
For the future, one paradox is that the countries that would benefit most from fluoridation, those in which large number of people are living in poverty, have the least in the way of the infrastructure needed to implement such a program. In the rich world, in countries with strong public health care systems and strong central governments, there tends to be strong support for investing in this and other forms of preventive medicine as they reduce the long term costs of public health programs.