I don't see it as a thing to get sales. Not at all. I view this as Tesla finally getting around to providing what they always were going to. Very little people will know about this update unless they really follow Tesla, and heck they may not even notice the option to activate it!
I don't think 40k have been produced so far. I think total MS refresh numbers are probably just above 20,000 at this point, and I would think anywhere between 7,000 and 11,000 of those are Plaid. The lines are still ramping, so they have a little bit to go before they reach 100,000 annualized.