Lorcana on Magic

[HyperspaceMountainPilot]

I just read an article from an author who experienced Lorcana on a Disney Magic cruise (with exclusive foil collecting opportunities)— does anybody know if it happens on every cruise? How long the sailing must be? How long it will continue? Can you book it before boarding or only onboard (it appears to require you to select it as an onboard activity in the app)?

Trying to decide if we should book a last minute voyage.