Not sure that's what happened here but regardless, should a world championship be decided on a course that hasn't been tested before? What if there are safety concerns that no one thought about? What if someone says, "I'll donate 1 million dollars for payout but I get to host world's at my personal carnival course." Where do you draw the line?
I don't think you draw a line. You try to use best judgment---for an untested new course, for existing courses in a bid, and for special changes to existing courses, which we've often seen.
An untested course may not be "best practices", but it's one of the many factors the PDGA should weigh.