The dev process carries over from when we constantly rewrote the codebase from scratch every few weeks[0]. We ran many experiments, most of which we threw away. A small number became part of "pgrust". It didn't seem worth it to maintain public branches with all of our development effort when we knew 80% of it was going to be thrown away

[0] https://malisper.me/postgres-in-rust-regression-suite/

But you can make the branch public without committing to maintaining an experimental branch, this doesn't make sense.