Unlikely to happen unless they extend the route. Needs 2 stations as start and stop points. Although I'm in favor of just having the Capital Limited as set dressing. Would make the route more alive, and working around it would be interesting.
Even as an AI service, it would only run once a day in each direction. But it would be nice to see it with a rake of superliners now and again.
I think the P42DC would be great if it came with another route dedicated to it, but it also adds timetables to routes where possible (Like Sand Patch for the Capitol Limited or Peninsula Corridor for the Coast Starlight).