I have quested for this DRA grail myself. I seem to remember Matt saying on a stream that it was only one freight service that went into Dresden GBF to bypass Neustadt, but I have never found it. When people post videos of DRA EB freight runs on YouTube, I have also searched for it. The turnout is at kilometer post 113, allowing you to fast forward to the key moment to see if the service goes into the yard. There is a scenario that heads into that yard that I know of: The Pieschen Predicatment.
I have never seen a service pass through Dresden N. gbf station. Then I don't understand why this part was created.
I'm reviving this old thread (to avoid doing a second one), but I'm wondering to get an answer if there are any freight who go to Neustadt Gbf because I haven't found any concrete answers or service names on the forum, whether on DRA or DLG