Comment by btown

It was/is quite common for corporate projects that become open-source to be born as part of an internal repository/monorepo, and when the decision is made to make them open-source, the initial open source commit is just a dump of the files in a snapshotted public-ready state, rather than tracking the internal-repo history (which, even with tooling to rebase partial history, would be immensely harder to audit that internal information wasn't improperly released).

So I wouldn't use the single-commit as a signal indicating AI-generated code. In this case, there are plenty of other signals that this was AI-generated code :)