I don't know about the Wonder, but we had fireworks on Pirate Night while we were on the Magic in April. They said that Disney was the only ship authorized to have fireworks.
The fireworks have to be on a night that the ship is in port or leaving the port.
They are not allowed to carry the fireworks and have to pick them up at a port and them set them off that night. The ship is not allowed to travel with the fireworks onboard.
On our 14 day repo cruise, they had fireworks one night only (Pirates Night).
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