None of those investigations showed that parts supplied to Apple came from Xinjiang. Only that one of their suppliers operates a plant there. These suppliers are huge conglomerates with plants all over China. Apple is one of a tiny handful of companies that actually audit their supply chain, but they only audit the chain that actually supplies them.

From now on though any kind of audit in China is going to be almost impossible. They've started arresting researchers who perform due diligence reports for revealing 'state secrets'.