SE-0499 marked as Implemented (Swift 6.4), but isn't fully implemented

Hello, I tried to make a String of a non-copyable type: assert(..., "Unexpected foo: \(myNonCopyableValue)") but it appears that DefaultStringInterpolation does not support non-copyable types. Neither is there a String(describing: myNonCopyableValue) available. These APIs were accepted as part of SE-0499, which is marked as "Implemented (Swift 6.4)", however it appears the PR for these parts was not completed. Just bringing this to folks attention because I spent a while searching for this,...