While that sounds good in that specific context, there are two considerations.

If the number of people convicted is small, it only serves to set a precident for removing the right that could be applied to other criteria while not really having any impact on the voting results.

Having something like that allows for it to be weaponized against political opponents and their supporters. We can already see that with removing felons right to vote, which goes along with discriminatory convictions intentionally designed to negatively impact minorities.