I also wrote by email to HAL to ask that they make rebooking more flexible over coronavirus concernss.
Received this reply:
"Thank you for your recent correspondence with Holland America Line regarding the Coronavirus. We ask that you please call our special line for this issue at 1-800-577-1729. This line is available 7a-5p, Monday-Friday, 8a-5p Saturday and Sunday. All hours are Seattle time (PST)."
Same qualifications as always, YMMV, offers change, and it may not work for you. But may be worth a call to their special line.. Good luck!
(Reposted from the Apr 04 Nieuw Amsterdam Transatlantic thread.)