So Sony requested an "unlimited supply" for pre-order for the PS4. The PS4 has a date release. Even after the "unlimited supply" has been dried out, Sony is still taking pre-order and say that they do not promise day one delivery... They have over 1 millions pre orders around the world.
So let's assume they have heating issue, that will be the dumbest move ever to keep taking those pre orders while knowing your product is deficient with less than 3 months to release.
And in case they were to be that dumb, Xbox one can raise it prices to $600 and still win next gen