What is the issue with the Fetch Standard?

As per the standard, Response.body returns null if the body is null, https://fetch.spec.whatwg.org/#dom-body-body and https://fetch.spec.whatwg.org/#ref-for-null-body-status. However, no browser implements this. In all the implementations, a 204/205/304 response etc. would result in a Response.body of an empty stream.

Perhaps the fetch spec should be fixed to reflect implemented reality?