Do you have data supporting that Tesla replaced 2 million gasoline cars? Selling electric cars does not mean that the buyer has gotten rid of their gasoline-powered cars, and it's not uncommon for one person to own multiple cars.
I have no reason to assume Tesla encouraged more people to become car owners. That would be quite the expensive status symbol for a non-car owner to take up. And those who own a gasoline-powered car buying a Tesla as a second vehicle would still reduce usage of the first vehicle.
So assuming that most of those two million sales weren't in lieue of the sale, or at least use, of gasoline powered cars, doesn't seem reasonable to me.
But let's be extremely conservative in our praise of Tesla, and say that the company took one million gasoline powered cars off the road and replaced them with electric cars. That is quite the accomplishment if you accept the premise that electric vehicles are better than gasoline-powered ones for reducing the impact on climate.
