I don't know of any large open source project that doesn't require a CLA. As the post suggests, perhaps one day there'll be a Golang Foundation, which would otherwise have ownership of whatever code you contribute. See that Python has a CLA that gives the PSF ownership of your code: https://www.python.org/psf/contrib/contrib-form/
Even the linux kernel has a CLA, they just call it by another name (Developer Certificate of Origin)