If you're talking about the first link [0]: the conclusion of that study stated:
The major finding of this study is that TSH values are higher with a higher fluoride concentration in the drinking water, even for generally low fluoride concentrations. This is seen both in cases of untreated hypothyroidism and in controls.
...
cases tend to have higher TSH values (greater impairment of thyroid function) with higher fluoride concentrations in the water. Controls, with normal thyroid function, also have higher TSH values with higher fluoride concentrations, even though their TSH values are still within the normal range.
Table 2 illustrates the effect, showing a markedly increased level of TSH among people with an existing thyroid illness.
Do you dispute that finding?
I spent about 10 minutes looking up other studies on the topic, and pasted them here [1].
The first three found significant links between fluoride intake, iodine level and thyroid function.
The fourth study found a link between thyroid disorder and water fluoridation in different regions in the U.K., and included comparisons between fluoridated and non-fluoridated water areas.
The fifth, from Canada, claimed to contradict that U.K. study, however from reading the study in detail, it doesn't seem they compared fluoridated areas with non-fluoridated areas, and it's not clear there was a significant variance in fluoridation levels in the water samples tested. But it also didn't specifically look at the effects of fluoride intake on people with pre-existing thyroid disorders, the way the first study I referred to [0] did.
Having read and contemplated these studies, my take is that it’s probably the case that ordinary municipal water fluoridation is fine for people with healthily functioning thyroids and healthy levels of iodine.
However for people with low iodine and/or existing thyroid illness (which is likely to be largely the same group of people, given how crucial iodine is to thyroid function), municipal water fluoridation may exacerbate the illness, and impede recovery if/when diagnosis is made and treatment commenced.
Can you point to anything unscientific about what I've said, or about my decision to minimise fluoride intake, given that I know I have low iodine and that related thyroid impairment has been a major factor in my many-years-long debilitating health condition?
[0] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5805681/
[1] https://pastebin.com/KGiUBYLv