My comment on the GCC lwn article saying I hope GCC had consulted with lawyers beforehand was downvoted; not sure why. From this article:
Without a clear, organized mitigation strategy to assure that FOSS contributors keep their own copyrights, a project (such as GCC or glibc) that switches from a standing “(nearly) all copyrights assigned to a charity” model to a plain Developer Certificate of Origin (DCO) or naked inbound=outbound contributor arrangement will, after a period of years, mostly likely to have copyrights that are primarily held by the employers of the most prolific contributors, rather than by the contributors themselves.