I’m afraid there really isn’t anything a Game Master would be able to do. They cannot manually place you back on a list that you may have left or otherwise update your standing. If you qualified for a reward and didn’t receive it a Game Master may be able to verify that fact but based on the list of folks that qualify. If leaving the team removed you from that qualification they are unlikely to be able to change that.
That said, as far as I know, you only need to be part of the team until that data is collected, which should have already taken place since the rewards are scheduled to go out on the 21st.
I’ve reached out to get confirmation that I’m correct and will update this thread when I get a reply.