First. Thanks to HN for not demanding phone numbers: anonymity allows to say things that cannot be said.
Second. Many googlers read HN. In some sense, HN is the extension of the internal forums.
CNBC made a good summary and I can comment on each bullet point.
Larry and Brin probably stopped attending because nothing important is said on TGIFs. More people -> more leaks -> less interesting information -> less attendence. Nothing surprising here. Sundar's solution seems to be resorting to boring once a quarter all-hands about business strategy. I wonder what the attendance will be.
It's a hypocrisy to complain about troubles with trust and at the same time ban political or whatever discussions. Googlers are generally very smart folks and understand that whatever they say may be used against them in the future, when policies change once again. Today you post a memegen where you state that triangles are better than squares, tomorrow you get fired because squares have become the symbol of some protected class. You have to apply a form of forward self-censorship and be very careful about what you say to whom.
I don't think there is a tension between execs and workers, but only because the two classes live in different worlds.
Don't get me wrong. Google is still the best workplace with top notch pay, but as it's got big, it's also morphed into a typical big corporation with typical corporate politics.
Just my 2c.