No they won't almost all the money difference is r&d costs that not only are already spent and thus sunk costs, but they still need to invest as not only does other countries demand it, it is a safe bet that there will be a legal change in a few years going back.

all they can do is maybe make some cars that currently are non-compliant but they will only do that if the jigs are still around and in good shape. They will not invest millions recreating worn out jigs that are not compliant and thus at risk of being useless whet the rules change again.

manufactures want consistency and predictability of policy because they have to make long term investments. This looks short term and so while they might take advantage it doesn't change much and in turn doesn't save much if anything.