Pretty sure the actors were cut after the media launch night.
But does the person chosen to direct the creative design really have that much say anymore? With Walking Dead, is that really what John Burton thinks is a good idea? I doubt it, but he was probably handed the plan and still went on camera saying the scripted 'most terrifying ride ever made' line. We still got exactly the same kind of ride as Merlin had been making for years sadly.
While Bradley Wynne seemed to love giving rides M Night Shyamalan-style backstories. (Sub Core Energy, A.C.R.E in Zufari, The Phalanx, the Boenen..) But Wicker Man's theme turned out really well in the end and was a lot more than just a naff backstory on a screen. Was this because he personally had a different vision? Or was there a change of attitude from others?
I dont know. But the way Merlin design things seems to be the way the massive movie studios direct movies these days. They will employ a director-for-hire who they know will reliably deliver what they already want, rather than a director whose allowed to have their own style or vision.
Not calling them puppet directors but who is directing becomes mostly irrelevant, in a company like this. Unless you get a real maverick who bends the rules and gets away with it, then you might have some more creativity slip in.