So by your definition, a book can be ‘canon’ but not scripture...
Wiki gives the more common definition:
“”A biblical canon, or canon of scripture, is a list of books considered to be authoritative scripture by a particular religious community. The word “canon” comes from the Greek ... meaning “rule” or “measuring stick”. The term was first coined in reference to scripture by Christians, but the idea is said to be Jewish.”
But if you want to argue that Protestants are right about the canon of scripture, and that the Catholic Church has the right to read other texts during their services...I think you will find total acceptance by Protestants.
Looks like it is the same meaning only “leftist” wiki did not want to include the word “Liturgy.”