Switching from one vendor to another could come from any number of reasons. Also, their work on supply-chain security is also at the same time that Apple was m

Switching from one vendor to another could come from any number of reasons. Also, their work on supply-chain security is also at the same time that Apple was more publicly promoting the security of their own hardware. So those two things could be entirely co-incidental. That said, short of a release of internal documents, I don't think anyone outside has a decent idea of what's going on.