They still can’t rescind it, they can only try to change the formula that determines which states fall under the law, and Holder will still have the power to disapprove all the changes to states which fall under the new formula.
Basically, we don’t know yet whether this will really be an improvement. Hopefully, it will, but it could also just expand the number of states that are under Holder’s thumb.
as of this second there is no formula. As long as none exists there is no way to object.