way to maintain voter rolls
Registered voters who fail to vote for three years and then don’t respond to a letter from the state are moved to “inactive status.” Inactive voters can still participate in elections.
Voters who remain inactive for two federal election cycles without voting or having any other contact with election officials are removed from voter rolls.
The 'purged voters' did not vote nor did they respond to the notification from the state.
No-one was 'purged' for moving.. they were removed after missing multiple elections in a row and not responding to the letter sent to them. The GA law declares that those people have 'moved' since they didn't answer.
The Supreme Court ruled that procedure was valid.
https://politics.myajc.com/news/state--regional-govt--politics/supreme-court-allows-voter-purges-states-like-georgia/TJZqgnWEAWOBvUMdB9eDOP/