The median was included as an item in the negotiations that Selig Enterprises (Suburban Plaza's owner) and MANA conducted in 2011 as Selig sought a variance to reduce the number of parking spots at Suburban Plaza. The memo of understanding that resulted from these negotiations is accessible through this post. Item #32 describes the median:
The median changes traffic patterns so that the Moe's exit on Church Street is right-turn only. The median also prevents left-hand turns from the northbound lane of Church St. into the the Moe's parking lot. To transport delicious southwestern fare via North Decatur Road, patrons using the Church St. exit should turn right on Church, then right again to drive through Suburban Plaza and finally exit at the newly installed traffic light on North Decatur Rd.
Eric provided the following visualizations. We will follow up with a photo of the new median as soon as possible. MANA is also making inquiries about signage to ensure patrons become aware of the new median from a safe distance.