وكان المشركون يسمّون أنفسهم حنفاء
The polytheists called themselves hunafa’ and claimed a connection to the religion of Abraham. Some older Abrahamic rites persisted among them, alongside beliefs and customs that contradicted Abrahamic monotheism.
Here hunafa’ describes a historical claim of affiliation; it does not certify every subsequent practice as authentic. Claiming to inherit a prophet’s tradition and actually conforming to it are different matters.
Consequently, the Qur’anic response addresses what people believe and do, rather than accepting a communal label as proof of correctness.