I think the point is that an “open source project” is more than just the code and license, it’s also the community that builds and maintains it.

A fast rewrite of Bun in Rust has effectively alienated most of the people in the Bun community, so in that sense the “open source project” has died. It’s no longer a community project, it’s just become a personal project again.

Just so everyone know, Bun is and has always been owned by a YC funded org with full time employees. The overwhelming majority of commits came from them.

A reset is very different from not being open source any more. If losing most of the community would mark a project dead in open source terms, then every new project would be dead on arrival. And that would just be silly.