AWS employees may not speak out very often, but they hardly need to. AWS is a marketing machine, from Jeff's regular blog posts, to the volume of free information they provide and to the conferences that they are running everywhere. I think Microsoft is starting to catch on with Azure promotions & conferences, but it's like Google didn't even know that the there was a race .... and they left their running gear at home.
For me personally[0], the difference isn't being able to speak in terms of marketing, but in terms of engaging with users who have problems. It may not translate to much in terms of run rate, but I like to think (or at least hope) the presence of GCP staff on HN, Stack Overflow, and in any other community we happen to be part of will in the long run pay off in terms of goodwill.
I am free to comment on posts about GCP here on HN. If there are workarounds, I can post them. If it's a bug I can comment as such and file it internally. I can express opinions as long as they're clearly marked as my own. I didn't have to take any training or end up on a whitelist; Google expressed their faith in my good judgement when they hired me. If nothing else, it was a morale boost to feel trusted to act responsibly.
At the other end of the spectrum, GCP has started building out in terms of large-scale engagement. Cloud has been a big part of Google I/O; now there's GCP NEXT as a Cloud-specific user conference: https://cloudplatformonline.com/NEXT2016.html. Building more in this space seems easier to me than a cultural change which encourages (rather than prohibits) customer and community engagement on the individual level, but perhaps I'm being naïve.
[0]: I currently work at Google on Compute Engine; I formerly worked at Amazon, although not on AWS.
