It’s unclear if the fire is related to the work that was being done, but that certainly seems plausible.
First reported by Universal Parks News Today, the fire was apparently localized to the Popeye and Bluto’s Bilge-Rat Barges attraction.
The black smoke was reportedly gone fairly quickly so it seems that whatever caused the fire was brought under control quickly.
The good news there is that the ride, and much of the surrounding area, had been recently closed down for a significant ride refurbishment, so there were no guests and likely limited staff in the area.