This is curious - I maintain 2 projects with 2k cumulative stars, and I was able to claim the free access. Wonder what the metric is? Maybe creation date has something to do with it?
Yeah that just redirects me to the paid page. I do wish the criteria were a little more transparent.
I get " Congratulations! You are eligible to use GitHub Copilot for free." that was unexpected but in retrospect https://github.com/NixOS/nixpkgs/ is pretty popular. (Currently 9.8k stars)
I have a repository with 625 stars, but it redirects to the subscription page.