I was myself skeptical of Wicked for a long while. I viewed it as trendy and not suited for a long-term "land" project. You can find posts from me like that as of like, 2 months ago.
I've come around on it. I think the strength of Oz really carries it over the finish line. It's one of the biggest and most iconic broadway shows of all time, strengthened by its' deep connection to one of the most iconic classic films ever. The Wizard of Oz is iconic to a fault, where it's almost difficult to rewatch because it's been remixed and parodied and retold just so many times. It's also a story with a long history of theme park adaptations, big and small. There's a reason why Disney World chose the Wicked Witch scene to debut one of their most impressive animatronics ever, at the time.
If you play into those classic and universally recognizable elements, and strengthen it with iconic characters and moments from Wicked itself (Elphaba, Glinda, Defying Gravity, Pink & Green, Popular, No One Mourns the Wicked), you'll have a land that makes total sense within the whole that is Universal Orlando Resort.