Aha! Thank you for that! They had the exact same PDF file that I was talking about from earlier, except now it says that it's effective until 5 April instead of 29 March.
The NCDOT website, www.bytrain.org, often has more accurate and timely info than Amtrak's website -- for trains that transit NC.
Fair enough. Thanks!
It will be taken down soon, but there is a service alert on the Silver Star schedule change on the Service alert web page. Since this was a straight five hour shift in the schedule, they did not put out a revised PDF time table.
Both resources give a completion date of 5 April, so I assume it's safe to say that this is the last week of revised schedules.