The issue was brought up at the Texas Reunion. SR originally began with a single tail gunner. The second was added so that one tailgunner was to drop out and assist a rider when they tapped out. With the addition of all of the chase vehicles we now have, the reason for the 2nd tailgunner has been superceded, hence we are going back to a single tailgunner. At least that is the understanding that I have from the explanation.
Proper grammar is the difference between knowing your shit and knowing you're shit.