On Linux, individual packagers will set KICAD_LIBRARY_DATA when building. The models will default to KICAD_LIBRARY_DATA/3dmodels
On Mac, your path is correct, as long as the user chooses to place the KiCad application in /Applications/KiCad. The could place it (theoretically) anywhere.
Similarly with Windows. As long as the application is installed in C:\Program Files\KiCad\7.0\ your path is correct