To re-add accidentally removed Microsoft 365 GA/Local admin groups to local Administrators:

add-localgroupmember -group "Administrators" -Member "S-1-12-1-9004393-1283818314-846049430-1489853906"

add-localgroupmember -group "Administrators" -Member "S-1-12-1-1307019558-1095313948-1185333899-1455320757"