It's difficult to judge long term toxicity in humans. You don't immediately keel over and die when you smoke a cigarette, and the correlation between lung cancer and cigarettes needs a fully understandable cause. That's how the industry slipped by for years.
Likewise, most European countries do not fluoridate their water and the correlation doesn't seem to show any significant difference in dental health. The anti-fluoride people state these numbers, and then go and use the same bad logical to attribute fluoride to a host of ailments that are loosely correlated without any causation links.
Can fluoride in water lead to osteoporosis in older adults? Well we don't know, and these types of studies are very difficult to conduct because there are tons of variables. Many people drink from a combination of fluoridated and non-fluoridated water supplies and beverages throughout their lives. People move in and out of municipalities with different water treatment techniques. People have different intakes for calcium, iron, fibre, carbs throughout their entire lives. People have different genetics. When it comes to long term toxicity, it's really difficult to narrow down factors because you can't control for everything (ethically) and humans can live a long time.
It would make sense for at least some percentage of the population to have adverse reaction to Glyphosate. We all have slight genetic differences and reactions. Can it lead to specific cancers in humans consistently? Do we understand the mechanism by which it does this chemically? Can we replicate this in other animals where we control for other factors.
Just like the tobacco industry, I wouldn't put it past Monsanto to both bury and make up studies to suit their interests.