It mostly legalizes European trainsets with minor adjustments, though Japanese sets would need significant reworking since they follow yet another standard. But this is important, because an FRA-compliant vehicle at 220MPH basically does not exist, and those have become legal if in their own exclusive right-of-way; and alternative compliance trainsets can now operate with regular American freight trains below 125MPH, which is basically the entirety of the network today anyways.
It mostly legalizes European trainsets with minor adjustments, though Japanese sets would need significant reworking since they follow yet another standard. But this is important, because an FRA-compliant vehicle at 220MPH basically does not exist, and those have become legal if in their own exclusive right-of-way; and alternative compliance trainsets can now operate with regular American freight trains below 125MPH, which is basically the entirety of the network today anyways.