I mean, to be fair, the beginnings of most movies with sequels don’t actually start by being titled, say “Back to the Future Part 1.”
The Fellowship of the Ring, for example, wasn’t titled “Lord of the Rings 1: The Fellowship of the Ring” if it mentioned Lord of the Rings at all, it didn’t imply a number, it just stood on its own. People knew sequels were coming, they didn’t need numbers to know that.
So to be fair to Wicked, naming it something like Wicked Part One is dumb anyway. Especially if it flops and they shelve the sequel for a tax break.
Nostalgia’s a helluva drug. I’ve done my best to try to avoid it, but we all like that hit from time to time.