They can keep using whatever they're currently using.
This doesn't take away anything. It's a new standard.
Based on your argument, one should add new safety standards to cars like seat belts, because old cars might not have them.
one shouldn't*
One shouldn't add new safety standards*
writing before coffee...
To be fair, some municipalities do actually require old cars to be fitted with seatbelts... air bags, not so much, because apparently changing a steering column is too hard?