When you say Second Amendment Sanctuary Cities, does that mean Gun-Free Zones?
No. It means that citizens in those counties will keep their guns and not be subject to any seizure of them, as their respective counties have passed resolutions to protect their 2nd Amendment rights (to bear arms) despite recent laws enacted by the [Democrat-controlled] Virginia House which contradict the Supreme Law (the Constitution).
And, according to my understanding of the law, sheriffs in those counties (and all across the US) have ULTIMATE AUTHORITY over their respective jurisdictions that would override any request or action taken by a National Guard or Federal Government enforcement agent.
RE: Localism: Emerging trend for 2020 as seen by the crackdown on the 2nd Amendment in Virginia and Elsewhere