Yes, that is a possibility. There is also this fairly extensive meta-analysis over a period of 20 years, that finds a "consistent and strong association between the exposure to fluoride and low IQ". [1]

There is, in other words, an undeniable correlation. The more interesting question is -- are there any safe levels of exposure, and what are the effects over time?

[1] https://link.springer.com/article/10.1007/s12011-008-8204-x