I just read, in the New York Times, that the gangway that fell had been installed on Friday, specially for the weekend visits. Therefore, the investigation will likely focus on how the gangway was installed and secured, at both ends, especially since the ship, itself, would have all the apparatus to make sure the gangways, at the various ports, would be secured when the ship comes in.
The ship's finishing touches will probably be completed while the investigation is conducted. I doubt this will affect the January 12th maiden voyage.
Again, my prayers are with the victims and their families.