The folder is filled with the extracted gameplay.bndl, since the retail gameplay wont work, i take it from the beta build, it should work for 
any game version, as long as it has the multiplayer and dlc

if you gonna modify the races or jackspot locations, use the base for the, well, base, or use the one from
jackspots only folder, it has the base + modifed jackspots, afaik its the same as in the modified folder,
so if you wanna edit the races or jackspots, make sure to remember the filenames