I think that is really stretching the practicality of the term in order to label something genocide on a technicality based on ideological dogmatism. It is really hard to imagine a genocide where a single person is not killed. Even ignoring that, genocides always lead to a refugee and emigration crisis which also did not happen in the case of the Uyghur.

By the Chinese government’s own statistics, birth rates in Hotan and Kashgar fell by 60% from 2015 to 2018.

Is that enough to determine genocide? What were the birth rates after this drop? Were they in the red, leading to population reduction or stagnation? There are explanations to this drop that are not genocide. For example, ethnic minorities in China have always been lenient targets of China's family planning policies. It is possible that the Uyghur were subjected to stricter family planning post the terrorism crisis for reasons other than genocide.

Many of the "china-watchers", like Adrian Zenz, are anti-abortion, white-supremacist christian evangelicals. They view any reduction in birth rates as a genocide, even if that reduction is caused by more access to birth control. Birth rates in liberal countries, especially in countries like France, Japan, South Korea, the UK, are tanking. Do you agree with the birthers that this constitutes a genocide? (they would call it a white genocide).

We also see lower birth rates in countries that have higher economic development in general.