Halloween fest in ocean park and disneyland, hong kong.

We planned to visit the park on 22nd Oct.. but now I saw in the website that thr is a Halloween fest on that day.. so we decided to change our visit date to 19 or 20 Oct when there is no fest to avoid huge crowds.. Is our decision right?

Similarly can someone help me with Halloween in disneyland ,so that we can decide our visit accordingly..
thank u..