In short, Kentucky plant has to diminish some of the extreme production-related costs. They already did it in the Tsutsumi plant in Japan with the introduction of the cost-cutting production system.
Interestingly enough, Toyota did invest $1 billion in the Kentucky plant. Yet, the investment did not prepare the company for the cost-cutting production system. If it did, freed up cash would end up in the Research and Development division for electrification and artificial intelligence.