The Assistant Secretary of State calls it a "wholesale disenfranchis[ment]." He's fine with correcting names through incremental research.
Purging the rolls is a horrible idea. The people least likely to re-register are most likely those who are already under-participating - the poor, working, youths, communities of color, and new voters. That"s because forcing re-registration drives up the transaction costs of voting, and many of these groups generally have less time for increased costs, and are already in need of language assistance and other civic engagement efforts.
As for the pro-democracy movement, it ought not get stuck on the defensive. It ought not let itself be forced to put its resources behind re-registration drives.
It should counter the EFF proposal with a plan for full, automatic voter registration in Washington state.