A lot of veterans were improperly added to the NICS and have a hard time clearing their names. The process to get off the NICS is perpetually underfunded due to Sen. Schumer. People who have had their rights wrongfully taken from them have to spend the time and money getting a court order to get their rights back.
The NICS would still show them as citizens. Unless they were added as felons, they would be able to vote.
Where is the potential for abuse?
And even better, the RATs would suddenly be totally on-board with a way to clear up erroneous entries, since it would now benefit them.