Have to wait for the next Snowden before you get any citations.

NSA collaborator or not, the mere existence of something like Cloudflare, which also tries to nudge you into skipping internal http/tls and just use that at the front, makes it highly likely that NSA is already deep in their infrastructure, just like they've been in the past for literally any big technology company in the US.

But yeah, zero citations, zero evidence, just based on history and what the goal of the organization is, it's pretty clear what's going on already.

So just conjecture and speculation, then.