They probably have rights to the project under the respective contracts they have with the employees. That aside, having "<new project> by ((Google(|rs))|<$big_corp>)" in the title has generally been a reliable filter for projects that do not stand on their own merit, and this one seems to be no exception.
As an experiment, I deliberately avoided adding "by Google" or similar when first submitting FOAM to HN while it was being tweeted about after yesterday's EmpireJS talk: https://news.ycombinator.com/item?id=9442943
Over on /r/javascript, my plain titled link has 2 points/23 comments while the "from Google" submission has 44 points/65 comments.
Not of much use for direct comparison purposes (GitHub repo links vs. project site links, different times of day, weekend vs. weekday etc.) but mildly interesting.
