The big problem is that the old way didn’t work for forums that required people to be logged in. The new way shows the login screen if they’re not logged in, and then takes them back to the topic.
What you can do is to change the mailout template to use HTML and set the mailout preference to HTML or both. that way you can put the shortcode inside an a tag that will simply hide the long URL.
For example, in the mailout template screen under Forums > Email Notifications, add this:
Topic URL: <a href="[topic-url]">[topic-title]</a>