Maybe, the manager will cut a percentage from the campaign above,
I tried to see the group of bounty managers. they claim it's just a free gift for bounty participants. The final reward will be distributed in the next month or so after being registered with CMC.

Somehow I'm not sure about the bounty manager's reasons. some have been distributed according to the spreadsheet, and some have not. but they claim it as a free gift. that's a bit suspicious.