For example, the claim that the “Jewish canon” was determined at “Jamnia” is at very best, a “hypothetical”. It’s a Roman Catholic fantasy or worse.
Note that the article contains the following footnote:
5 There is debate as to whether the Council of Jamnia actually "closed" the Jewish canon because debate continued among Jews for hundreds of years afterward as to which books should be included or excluded. Even into the 3rd century A.D., controversy surrounded Ezekiel, Proverbs, Ruth, Esther, and others
The point is that the Jewish canon was not fixed until well into the Christian area--possibly even after the Christian canon (consisting of all 74 books) was fixed in the 4th century. At Jamnia, the Jews there were mostly concerned with identifying and rejecting what was NOT Scripture-- including some writings that are now part of the New Testament. The Christian Church, already in existence, could not be bound by Jewish teaching authority.