Amtrak California Zephyr extra cars today?

Does anyone know what is going on with the westbound California Zephyr today? It seemed to be an extra long train (4 sleepers and 4 coaches if I counted right?) and an extra lounge and diner on the end. Then it left the extra diner and lounge in Denver. Is this some sort of equipment transfer to get ready to reactivate the Prarie Wind or Desert Wind trains to Seatle & Las Vegas again? Denver is where the Prarie Wind would split from the Zephyr in the 1990s, so we always had extra diners, lounges, and coachs sitting around.

I doubt Amtrak is starting the Pioneer or the Desert Wind again. Lately the only additional Amtrak routes/trainstarts have been state sponsered and I haven’t heard anything about that. Besides I doubt Amtrak has the extra trainsets to start a service like that right now.

Further mystery. The cars were gone this morning, so that means one of two things. Either the eastbound Zephyr must have taken them last night, or they were sent somewhere to be shopped. Other than the railroad shops the only passenger car shops I know of around here is Rader Railcar. Does anyone know if Amtrak outsources their work?