When they first introduced these Governing Body Helpers in 1992 they stated this
Their being assigned to work with a committee does not give them a special status. As Jesus said concerning his disciples, “all you are brothers.” (Matthew 23:8) However, much will be entrusted to these men, and consequently “much will be demanded” of them.—Luke 12:48. (W 92 4/15 pg 31)
Apparently they have no special status but that doesn't stop the GB acknowledging their position by calling them GB helpers, just like the GB identifies themselves as such. This is just another tier in their class system.