If I see in the code correctly this flag doesn't do anything anymore? Can you check @diosmosis ?

It should basically skip archiving a segment in today's timezone (I think unless it was created or changed recently see https://github.com/matomo-org/matomo/blob/3.14.1/core/CronArchive.php#L2000 ) see https://github.com/matomo-org/matomo/blob/3.14.1/plugins/CoreConsole/Commands/CoreArchiver.php#L105-L106