Post 2011 Boeing made a design change to use motive flow from the main tank jettison pumps for the center tank scavenge system because it was a higher pressure source. If the main tank jettison pumps are inoperative on these airplanes, the center tank scavenge system won't work. There is a series of ADs requiring this change and other associated scavenge system changes due to freezing of the scavenge system trapping some fuel in the center tank (2015-07-07, 2016-11-03 and 2019-16-13).
The weight limit the OP quoted tells you to only take credit for center tank jettison, not main tank jettison, when calculating your return to land climb limited weight when the main tank jettison pumps are inop.