The Holy See approved the Neo-Catechumenal Way's form of celebrating Christian Initiation, which is different from the normal Rite of Christian Initiation (RCIA) celebrated by the Roman Church. But why only the Christian Initiation and not the way how they celebrate Mass? Well... Vatican officials gave wonderful statements to tell "The Way" and the whole world what the Eucharist and liturgy is. I quote two below:
"With respect to the celebrations of the Holy Mass and the other liturgies of the Church, follow the norms of the Church as indicated in the liturgical books – to do otherwise must be understood to be a liturgical abuse."
“But also during the way, it is important not to separate oneself from the parish community, and particularly in the celebration of the Eucharist which is the true place of universal unity, where the Lord embraces us in our various states of spiritual maturity and unites us in the one bread that makes us one body.” - Pope Benedict XVI
