This AKN article (dated Jan 27, 2017?):
https://knowledge.autodesk.com/support/autocad-civil-3d/troubleshooting/caas/sfdcarticles/sfdcarticl...
The described procedure to 'WBLOCK the entire drawing', completely destroys Parts Lists assigned to Pipe Networks - the Parts Lists and Pipe Networks are still there - it's just that each-and-every-single Part within said Part list has been erased, which is kind of a big deal.
Any chance you'll fix the WBLOCK Command?