We don’t. When we speak about the Roman Rite, we are meaning the rite of the Roman Catholic Church currently in use, the so-called forma ordinaria. Pope Benedict XVI amplified the possibilities for celebrating the liturgy of the sacraments according to the previous form, as it was in use in 1962, which is now the forma extraordinaria of the unique Roman Rite.
Even those who do not use to celebrate according to the former form of this rite, must appreciate it to understand the contemporary one. Keeping the former living will be an enrichment for the current form that never will lose its continuity with the previous one.