Presumably this would apply to Blue Basic fares, because other fares already have free changes.
https://www.jetblue.com/travel-alerts#fee-waiverFee Waiver
Last updated: 12/28/2021 6:30pm ET
Information for Travel Agents.
JetBlue will waive change/cancel fee for customers traveling Tuesday, December 28, 2021 through Monday, January 31, 2022 to/from:
All cities
Customers may rebook their flights for travel through the end of schedule online in the Manage Flights section of jetblue.com prior to the departure time of their originally scheduled flight. Please note that any difference in airfare will still apply. Customers with cancelled flights may also opt for a refund to TravelBank. Original travel must have been booked on or before Monday, January 31, 2022.