Looked all over for kicad.pro that the manual says must be changed to reset default libraries. Search of these FAQ provided many unresolved links.
The answer is to forget about the kicad.pro template file and look for sym-lib-table and fp-lib-table in /Users/yourHome/Library/Preferences/kicad. These are the files you may want to delete so new ones get made. Of course make back-ups and save the files so you can recover if needed.
More info can be found in the FAQ here:
Version: (5.1.9-0-10_14), release build
Platform: macOS Catalina Version 10.15.7 (Build 19H1030), 64 bit, Little endian, wxMac