A few questions, suggestions and concerns.
Firstly, I expect people who's criticisms I'd most want to hear to be very busy, I hope the contest will consider lower effort but insightful or impactful submissions to account for this?
Secondly, I'd expect people with the most valuable critiques to be more outside EA since I would expect to find blindspots in the particular way of thinking, arguing and knowing EA uses. What will the panelists do to ensure they can access pieces using a very different style of argument? Have you considered having non-EA panelists to aid with this?
Thirdly, criticisms from outside of EA might also contain mistakes about the movement but nonetheless make valid arguments. I hope this can be taken into account and such pieces not just dismissed.
Fourthly, I would also expect criticisms from people who have been heavily involved in EA over the years to be valuable but, if drawing on their experience, hard to write fully anonymously. What reassurances can you offer and safeguards do you have in place beyond trusting the panelists and administrators that pieces would be fairly assessed? What plans do you have in place to help prevent and mitigate backlash, especially given that many decisions within EA are network based and thus even with the best of intentions criticism is likely to have some costs to relationships.
Reading the title of this post I thought it was a decade review of the effective altruism movement. Are any of the EA orgs working on that?