Theme unit testing irony: Post without title yields 404 with get_permalink()

I am testing with theme Twenty Sixteen, which follows WordPress’s theme unit testing advice for title-less posts:

(no title)
Lack of post title should not adversely impact layout.
Post permalink should be displayed. Making the post date a permalink is a great solution. See Twenty Ten for an example.

This does not work with the Post Name permalink structure (http://myblog.com/blog/my-post-title/) or with any other permalink structure that includes the post title.

A permalink is created for the title-less post using the post ID:

http://myblog.com/blog/123/

However because of the Post Name permalink structure, it is looking for a post titled 123, not a post with an ID of 123.