Adding the closed days. I had read a post that the number of days the parks are closed has not been added yet because the CMs need to be onsite for that. Disney has said that the passes will be extended for the number of days the parks are closed (so March 16-July 10 inclusive, which is when parks were closed):
“If you are an Annual Passholder who has paid in full:
All active Walt Disney World Resort theme park and water park Annual Passes will be extended for the number of days the parks are closed. The new expiration date will be reflected on the Annual Passholder’s account prior to the reopening of the parks.”
https://disneyworld.disney.go.com/experience-updates/annual-passes/