No, they can't do that... the top speed limit (I think) is written within the car spec's. I think 2021-2023 model years will continue to have the full original speed limit.
It's possible that the new lower speed limit is related to new tires limit.... I would gladly use those tires next time I change my tires if they are more efficient. I don't see why I would ever exceed 90 MPH on the US anyway. I drive the car with passion but I never ever exceed speed limits by more than 10 MPH, and I never ever take my car to tracks. 150-130 MPH is just useless for me and hence I would gladly take a more efficient tire. I hope that this is the reason for the lower speed limit really