My understanding is that Apple PCC will not open source the entire server stack. I might be wrong. So far I haven't seen them mention reproducible builds anywhere, but I haven't read much of what they just published.
One of the projects I'm working on however intends to enable just that. See system-transparency.org for more. There's also glasklarteknik.se.
Then shouldn't they allow us to self-host the entire stack? That would surely put me at ease; if I can self-host my own "Apple private cloud" on my own hardware and firewall the heck out of it (inspect all its traffic), that's the only way any privacy claims have merit.
