A few days ago, on their website, Disney announced that in accordance with the CDC conditional sail order, all cruises longer than seven nights are canceled. This announcement is very minor, as only three cruises are affected. The Magic's 12-night transatlantic cruise from May 9th to May 22nd is canceled, a 9-night Alaskan cruise on the Wonder from June 18th to July 7th is canceled, and a 9-night Southern Caribbean cruise on the Fantasy from July 22nd to July 31st is canceled. The Dream is unaffected by this announcement, since it mainly does shorter cruises, typically of 3-nights and 4-nights.
Though it may seem like it, not all cruises in 2021 that are longer than seven nights were canceled. The Magic is scheduled to do quite a few European cruises that are longer than seven nights. These cruises are possible since they don't visit any US ports, so the US CDC doesn't have any control over them.
As always, all of the people affected by this minor suspension will have the choice of receiving a full refund or a 125% cruise credit (as long as they've paid the cruise in full). Be sure to check the Disney Cruise Line website for more information and the latest updates. Also, the CDC website is another good resource for information about travel and cruise restrictions.