These are experienced members of the community who have demonstrated both excellent technical acumen and the ability to build consensus and understand alternative perspectives. The language team will trust them to help steer discussion on RFCs and guide them towards a useful conclusion.
They’ll be joining lang team meetings as well.
You can read more about what shepherds do in the initial post about them. But in general, you should expect to see these fine folks increasingly active on language RFCs, and they’re good people to reach out to for helping unblock, revise, or write RFCs.