There is some discussion on this thread that you might find useful.
https://boards.cruisecritic.com/topic/2980841-dover-to-heathrow-return/#comment-66716479
For frame of reference, the Silver Moon left Athens January 16, going around Africa, arriving Mumbai February 14. Thus suggesting Symphony could do similar canceling Singapore to Mumbai to Athens, March 12 - April 13 sounds like a possibility.
I don’t board until Bangkok going through to Singapore. I look forward to meeting you and others.
Russ Grieves is currently CD until Singapore at which time Vicki van Tassel takes over. Gordon Porth will be in Cove from Bangkok onwards. Colin Salter replaced Dan Davies in the Avenue in Sydney today until March 12 at which time Dan returns. Carl Wishneusky is Guest Entertainer from Bangkok to HCM.
SS is just starting to address its Feb 12 sailing from Mumbai to Singapore. As Crystal’s sailings are one and two months later, as bayonejoe says, it’s too soon to expect an answer to such a fluid situation so soon.
https://www.msn.com/en-us/travel/news/these-two-cruise-lines-canceled-sailings-to-avoid-the-red-sea-amid-attacks/ar-AA1n8ZtV?cvid=f37b0865a46c4eef95c0c61f9fd0df16&ocid=winp2fptaskbarhover&ei=9
Another article