Just got it in the email too.
It means every claimant? And where are we supposed to find a japanese speaker/writer within the next week?
That was not clear to me....
To my understanding it is referred only to the ones that want to dispute their case outcome, whether is accepted or rejected. If you have no problem with the amount that is assigned to you, then you don't have any reason to fill a dispute.
To be sure, ask Dargo here:
https://bitcointalk.org/index.php?topic=290799.new;topicseen#new