I'm skeptical of that claim, simply because it will take years to build up Gigafactories to handle the volume of production. Not just forcars, but busses, delivery trucks, maintenance vehicles, agricultural equipment, and big rigs too.
The transition from petroleum to electricity will take place, but at a more deliberate schedule IMO. I would change my mind if after the next 5-year cycle, automakers like Honda started transitioning their bread and butter cars like CR-V to fully electric platforms.