So I finally managed to get to an Amtrak agent on the phone. He confirmed that due to "some problems" the Coast Starlight is only running between Sacramento and Los Angeles and there are no sleeper cars available to use (where did they leave all the sleeper cars? In the Oakland yard?).
I'm not sure where they are being left, but the sleepers and the dining car will be removed until the outage is over. I guess someone thought that since this basically amounts to a 14 hour, in state day trip, the resources are best utilized elsewhere.
He did not know for how long it is going to continue like this, and surprisingly, in true incompetent Amtrak style, there is ZERO mention of this major disruption on Amtrak's Service Disruption webpage-
https://www.amtrak.com/service-alerts-and-notices. The only CS related advisory is related to trackwork in Oregon which is a different problem than this curtailed sleeper-less service.
The advisory you posted is the root of the problems. The track work had a bus bridge working between two points. Then, part of the tunnel collapsed. UP (the host) announced several estimated dates of completion. None of them have come to fruition and as of yesterday, the outage is indefinite, with a continuous curfew.
This new operating plan was literally announced and the affected passengers are supposed to be notified. It may take a little more time to update the website.
Besides, I can't wait to see the announcement. I'm sure it will be a winner and these things take time.
"Ride our contemporary train from LAX-SAC"
"The Dining and Sleeping Cars normally assigned to the Coast Starlight will undergo maintenance"
"We regret the loss of services on the Coast Starlight during this outage but it'll be back stronger than ever. Wait until you see our new dining car menu. They love it out east!!"