Releasing is hard to scale up like google have to. How many apps are they releasing to daily...!
It's not technical building blocks (they can all be automated), not even busy work, just complex intertwined dependencies from completely different, often non-electronic, domains.
Hypothetical release co-ordinator speaking: "Did app A release this morning into EMEA prod? Ok that means app B can go but only once the security review team drop their veto. Has release candidate 2 been promoted to the canary environment yet? Remember B's new deployment process is in scope this release, and do not release to the 5 servers in the BCP datacentre today..."
Could you imagine managing the constant evolution of a rules engine to replace a good quality release co-ordinator? I don't think i'd be able to sleep!
As far as i can see, continous deployment doesn't have the general applicability that continuous delivery enjoys.
Perhaps there is confusion in this thread regarding "PM". PM to a programmer may mean "Program Manager", but in most countries with parliamentary government, "PM" may mean "Prime Minister".