Paul VI referred to the NO as a new rite, I believe.
And he was honest in doing so.
"Two forms of the same Rite" is Benedict's attempt at the "hermeneutic of continuity", I think.
On the other hand, this phraseology does fit with the idea that the TLM was never abrogated but that the NO was introduced as an optional form.
In any case, whatever you call the NO it is completely different than the TLM. Some of it's 5,000 forms more than others.