The NEOCATECHUMENAL Way will eventually replace the regular catechetical teachings. Although I do not agree with this movement, it is fast forwarding its position on a tiny island of Guam. There is already a take over of those ordained in the Redemptorist Mater Seminary in most parishes, pushing out the local priests who are not in the NEOCATECHUMENAL Way.
Sad to say that on such a tiny island where Christianity is based not only on our strong faith, but for those who do not Walk the Way are being shunned and shoved to the side.
The Neocatechumenal way could eventually replace child catechism by rendering it redundant. Child catechism was already going through a rough time and then when other forms came along, the previous way did not have a chance anymore. This is a positive step in the right direction that will continue on.
The Neocatechumenal Way (or simply The Way) is designed for adult converts to Catholicism, not children. Specifically, it is finding the most success in China and the Middle East. The Catholic hierarchy has given tacit support to the way because it is bringing in members that otherwise would not have access to the church's teachings. However, if The Way were to begin competing directly with established churches for Catholics' attention, it would find that the existing charges of heresy would grow louder.
No, the Neocatechumenal Way will not eventually replace child catechism by rendering it redundant, because the old system is still what's in place. The Neocatechumenal Way has some small variations on the traditional catechism, but the Catholic Church has been so traditional that they would not likely adapt to the change.
The Neocatechumenal Way fails to attrach non-Catholic adults to Catholic teaching because many adults who could otherwise be moved to convert to Catholicism are already plagued by a lack of moralism and hedonism by the time they are able to dedicate the time to considering religions, especially Catholicism, which is viewed as stricter than other Christian sects. Also, child catechism allows for the soft minds of children to absorb Catholic doctrine more easily than adults and develop a worldview that meshes with Catholic teaching instead of fighting against antagonistic impulses that adults have.
I do not believe that the Neocatechumenal Way will replace child catechism. I think that while the Neocatechumenal Way will be popular among some believers, there will be some who are less traditional that will not agree with it. I think that it isn't something that will be universally agree with.