If the blackout continues indefinitely Reddit will probably install new mods on the popular subs and force them back open.
People could overwrite their posts and comments with empty text before deleting them and their accounts but even then there are probably backups that could be restored. GDPR makes that a little more risky for Reddit to do however.
Realistically the only way for users to win is to not play the game. Just leave Reddit forever and let it die like Digg. Even if Reddit backtracks now I’m not sure they can ever be trusted again.