I was at EmpireJS where this was announced and they said they had a team of Googlers working on it, and showed a few production Google apps built using it.

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.

FOAM is built by five Google engineers who are paid by Google to work on it full time. It is a Google "project" but not a Google "product".

I lead the FOAM team at Google.

Check the COPYRIGHT file in the repo.