The timetable should include the red BR 442 from Schnellfarstrecker Köln Aachen, possibly freight, and more locomotives to substitute in for the BR 182 or other regional services
I really hope there is a way to get more services onto there, it just feels a bit boring seeing the same two trains over and over again and for me lessens the replayability of the route.
I have been doing a bit of research, and the main problem is the lack of Leipzig Hbf were many of the other trains that could be on this route terminate. Still, it would be possible to have a playable RE 13 (Leipzig - Magdeburg) services from Dessau to Delitizsch, and than onto Leipzig Hbf (of the map) as an AI train. These RE 13 services are operated by a similar, but not the same, Talent 2 as the one already in Rapid Transit. Before the switchover to Talent 2s (which happened around 2016, the time the route is set in, the BR 182 is on this route for the same reason) these services were operated by BR 112s with Dostos. With Hamburg - Lübeck, these are coming to the game, and they would add a great layer to Rapid Transit. There might also be freight opportunities, but those are more difficult to do research on. I just hope some extra service layers come to Rapid Transit, as it feels a bit dead and dull currently in my opinion.