I'm not sure it is a larger scope, I've always understood this to be their role - they lead scrum meetings, but outside meetings they were the one that helped get the team unblocked. Managing the board was just a side-effect of keeping an eye out for any team members who were stuck.
On top of that the one I worked with who was good at this also took on small cases because otherwise he'd regularly have nothing to do.
On top of that the one I worked with who was good at this also took on small cases because otherwise he'd regularly have nothing to do.