The 1 million number isn't supported by any evidence. It is a claim made by China's detractors. If the pair-up program and forced rape were true then we'll see the Uighur population dwindle in the coming years. I expect, just like with the Tibetans, we'll be seeing the opposite. The pork-alcohol force feeding is fictitious. There's no evidence or even a slight indicator that China wants Muslims to eat pork or drink alcohol. This hasn't been shown in China's eastern regions and it hasn't been shown in Xinjiang either. As for your anecdotal claims from Quora, you'd forgive me if I don't take this seriously. If oppression was China's answer, then you have to explain why China is investing so much in education in Xinjiang. What's the point of funding all those Kindergarten students, only to oppress them and encamp them later?
From my perspective, it seems to me the United States is using Xinjiang as a sore point to destabilize China. From past experience, this is highly likely to be true. I speculate that in a few decades when the CIA finally declassify documents, I'll be proven right.