NCL cancelled all remaining March 2021 cruises today, so I would expect an announcement from DCL in the coming days. No way are they going to be setting sail before any of the 'big' cruise lines will.
"Updated December 29, 2020: Your safety is our #1 priority—both on and off our ships. Due to the current global environment, we are extending the suspension of cruises to include ALL cruises embarking through March 2021. Previously, we had announced the suspension of cruises on all ships except Norwegian Encore, Norwegian Escape, and Norwegian Joy. Today, we have added those three ships to the list of cruises suspended through March 2021. "