Beginning March 9, 2023, access will no longer be unlimited: World Mastercard and World Elite Mastercard cardholders will have 12 times per annum for 90 minutes each session.
However, the amount of data will no longer be limited.
Once the sessions are exhausted, you will have to wait until January 1 to get 12 new sessions.
Note that these changes only affect Wi-Fi on board aircraft (not Wi-Fi service on the ground).
This is clearly bad news for frequent flyers who will quickly exceed the 12 annual 90-minute sessions (especially on long-haul flights: 2 or 3 trips will be enough to prevent future accesses).