So here’s the second post, and I think I see the answer: To wit, WordPress will allow a very long URL. And, in this case, where I copied the title, then discarded the draft (because I thought the URL had been truncated), it appears that it automatically adds a “-2” (because the discarded draft is probably still around.
So I guess the answer is:
- Duplicate URLs shouldn’t happen–probably not even if you deliberately use precisely the same actual title (I’ll test that shortly)
- But WP URLs can get pretty long…
All things considered, I think this is preferable behavior.