I read an interview with the course manager, George Brown; Adrian's right - it was all about lengthening the 17th. Apparently it was too short for pros as a 5 (Romero got on in 2 with a Sand Iron in the Senior Open) and they didn't want to make it a long par 4, because par would have been 69. So they re-routed the 16th and pushed the 17th tees back
He did say that one of the benefits of doglegging the 16th was that it made club selection for the approach more critical and made the burn more in play.