Couple of thoughts: 1) citizens and people of ‘permitted to drive legally in US’ status who are newly passed drivers, such as 16 year olds, or are new legal residents to a state, “should be registered” ; all others would still need to request to be registered as long as they posses sufficient proof of the required state documents.
Driver’s license offices are often quite busy and the potential extra time to repeatedly ‘reregister’ every person who comes in (albeit every 4 years) may not be as practical as it sounds.
Concern should be stressed for the State AG offices to make extra effort to communicate with every licensing office for continual education to the acceptable vs unacceptable documents... quite a chore sometimes!