Sorry but I don't understand that response nor the problem. If you are manually copying from SP and pasting into a third party site a forum post (or topic) URL - then you get the exact url which is used by the forum. 

What is it that I missing please?

Check the screenshots, my new forum doesn't have the topic title and breadcrumbs like this forum and my old forum.

If you are referring to the actual URL: of a topic or post SP has always included the forum name and the topic name (and depending on circumstances, the post ID). Actually not always - but since about version 2. Or about 2008. You can not turn these url components off in fact.