Schneider has specific requirements for van and tanker regarding the 5th wheel. During their inspection, if it doesn't meet their requirements, they will ensure it does. Maybe that is what Box of TJ meant when he said they were being "rebuilt". Probably more like removed and replaced with a Schneider compliant 5th wheel.
Schneider 5th wheel requirements
Schneider approved sliding 5th wheel
Left side release
12 inch slider minimum
45-47 inch height from ground to top of 5th wheel plate (riser height could vary to achieve the 45-47 inch range height requirement)