Precisely.
The Vatican has allowed the Diocesan Bishops to establish norms for Communion under both kinds. The subsequent
USCCB document states:
The norm for reception of Holy Communion in the dioceses of the United States is standing. Communicants should not be denied Holy Communion because they kneel. Rather, such instances should be addressed pastorally, by providing the faithful with proper catechesis on the reasons for this norm.
Neither this wording, nor that of the GIRM, allows the abolition of kneeling. While (some) Bishops considered kneeling Communicants to be disobedient, the Vatican clarification of their original intent settled that debate and proved those Bishops wrong.
Nevertheless, if the norms themselves are to be
modified, the burden lies on the USCCB to do so. The GIRM gives them that
responsibility. For the Vatican to revise the norm directly would require that they rescind the original permissions.