gRPC was contributed by Google to CNCF. Google remains extremely engaged in its ongoing development.

https://www.cncf.io/projects/

You might also be interested that Google is hosting the first ever gRPC Conf, which is being organized by CNCF the gRPC community: https://events.linuxfoundation.org/events/grpconf-2019/

(Disclosure: I'm executive director of CNCF.)