Thank you for mentioning this.  I have added the stream's name in https://www.openstreetmap.org/changeset/181098426.

It's quite easy to add names to existing objects, so feel free to try doing this yourself if you have time.

You might find parts of https://learnosm.org/en/beginner/id-editor/ helpful, although those instructions cover adding new objects to the map rather than adding names to existing objects.