I was using Roll Call for my own search (round-trip Singapore, because those are easy to buy my own air) and noticed that a cruise matching that search for Silver Shadow in late 2018 no longer existed. And then upon further research, it turned out that all Silver Shadow cruises after September 2018 are now totally different.
And then I found end of 2018 changes on Silver Spirit and Silver Whisper too.
This happened with Silversea last year too - right before they are about to issue new itineraries, they reposition and rearrange previously released itineraries.
I only have an automated way to find itinerary changes on Crystal. SO if you ever happen to notice a change on one of the other lines that I track on Roll Call, I would appreciate a heads-up. Thank you.