It's not the version of the BLAKE3 hash algorithm (which has been finished a long time ago and won't change anymore), it's the version of the reference implemen

It's not the version of the BLAKE3 hash algorithm (which has been finished a long time ago and won't change anymore), it's the version of the reference implementation. The changes from 0.3.7 were just fixing a build issue on MSVC (this was release 0.3.8), and breaking changes to the API of the reference implementation, mostly removing parts of the API of the reference implementation which weren't stable enough for a 1.0 release.