To make a long story short, we are making changes to the incentives scheme behind the Founding Members program, in order to make it simpler, more transparent, and clear.
All useful efforts until this point are being honored, and rewarded (quite generously if we may say so).
As you can see, the potential rewards for contributing to Joystream are substantial.
You have until January 26 to report any of your contribution, after that point you will still be able to earn JOY (from a separate pool), and become a Founding Member, but you will not be able to report older contributions.
If you have any questions, ask them in Discord.