I can only repeat and confirm that, if you use the released GSX, the new fuel truck WILL surely come for the all the PMDG 737. It wasn't like that in the Beta, but the released version includes the proper refuel point for all PMDG 737 versions.
Check if you maybe have a GSX.CFG placed by mistake in the Airplane folder (instead of under %APPDATA%), because a file placed there is supposed to be developer-provided, so the Reset button in the GSX editor won't remove it, since we assume airplane developers will provide a correct configuration, so we don't remove it with the Reset button, you must remove it manually.