Last week, Disney made multiple official announcements regarding the status of Walt Disney World Resort in Florida and Disneyland in California. They confirmed that both U.S. Disney theme parks will remain closed to the public until further notice and extended a special dining plan offer to Disney World guests whose trips have been impacted by the unexpected closure.
Now, Disney Parks & Resorts have issued a special offer for Disneyland visitors. The offer is available for eligible guests and is featured in full below:

The offer states that it is valid for Disneyland “Guests who booked a Walt Disney Travel Company vacation package to stay at Disneyland Resort during the dates that the Disneyland Resort theme parks are closed and through May 31, 2020.”
It also states that “reservations canceled before March 1, 2020” are not eligible for the offer. Since March 1 was two weeks before Disneyland Resort temporarily closed, travelers who canceled prior to that date were not affected specifically by the closure.

As per Cast Member information, the offer will begin today, Monday, March 30, 2020. Eligible Disneyland visitors will receive special rates at onsite resorts for most arrival dates June 1, 2020, to December 31, 2020. Discounts include 10% off the regular Premium Room rate at Paradise Pier and 15% off standard rooms or 20% off premium rooms at both Disneyland Hotel and Grand Californian Hotel.
If you qualify for the special offer Disneyland has extended to guests, call (714) 520-5050 to learn more.

The question of when Disney Parks and Resorts will reopen still remains unanswered. Although Disney has not confirmed anything regarding reopening dates, they have opened up resort reservations on the WDW website starting June 1. The Disneyland special hotel offer also begins with June 1 arrivals.