Franks' omission is the most surprising with the 108-cap Crusaders strongman a regular starter for the All Blacks, until this season. He was dropped for the second Bledisloe test at Eden Park earlier this month after a poor showing against the Wallabies in the Perth defeat a week earlier.
Laumape has seemingly paid the price for a congested midfield, with Sonny Bill Williams, Ryan Crotty, and Anton Lienert-Brown all competing for the No 12 jersey.
Uncertainty still remains over the availability of Brodie Retallick, who has been nursing a dislocated shoulder sustained in the draw against the Springboks, and whether Liam Squire will be included in the 31-man squad set to be named at Eden Park at midday.
Squire had ruled himself out of consideration for the Rugby Championship and Bledisloe Cup this year, but reportedly made himself available for seletion earlier this week.
The All Blacks will play South Africa, Canada, Namibia and Italy in pool matches starting on September 21, before heading into the knockout rounds.