I feel like the big companies have nothing to lose from saying and doing these things. First it frees them of any guilty conscience to hack and slash at 'extra fat', second it allows them to get away with running skeleton teams. Third, it makes people who get solicited and receive a job offer feel "lucky" that they were given an offer in a "bad market".
There's no reason for them to not act like this. Unless a pile of startups are standing around throwing more money at engineers and loudly attracting google's talent away.