I have worked at Google and Amazon. I never required PMs to be in the loop for a feature launch at either of the two.
Having said that, both Google and Amazon has excellent PMs and there are teams that require PMs to be in the loop for a feature launch but it is not universal.
Having said that, both Google and Amazon has excellent PMs and there are teams that require PMs to be in the loop for a feature launch but it is not universal.