Well it hasn't. "Production" for a language runtime means being generally available for arbitrary use. The engineers that built the runtime using it to release one closed source binary to the public is, at best, an extremely narrow beta test.
I don't agree that using something in a very specific environment is the same as a wide release.
I trust readers will either know the backstory or read the articles I link to. Such is life if they don't.
Do you think it would weaken the article?
When I said it would improve the credibility I did mean it. My instinct on reading the article this morning was "this person doesn't know that Claude Code runs on Bun, which weakens their credibility in presenting the argument they are making here."
You could argue that the release tag isn't important - but at the top of this comment thread a member of the team confirms they delayed the release to finish some extra testing. So the ambiguity around if the project is complete and pointing to the lack of a release mirrors internal sentiment as well.