Sinorhizobium versus Ensifer: may a taxonomy subcommittee of the ICSP contradict the Judicial Commission?

In response to a Request for an Opinion, the Judicial Commission (Opinion 84) confirmed the earlier synonym, Ensifer, as the correct name for the genus better known as Sinorhizobium. The Judicial Commission considered that this decision would not cause sufficient confusion to justify the conservation of the latter name. The Subcommittee on the Taxonomy of Agrobacterium and Rhizobium of the International Committee on Systematics of Prokaryotes (ICSP) publicly disagreed with this conclusion. Was it justified in doing this?