Is it your contention that the Jewish people didn't have any idea what writings came from God and were authoritative prior to that time? If so, then that would contradict Jesus's own words when He referred often to them (i.e.; Moses and the Prophets and the Psalms, "it is written", etc.). We also have the writings of the Jewish historian Josephus who in his "Contra Apionem" refers to the tripartite division of the Old Testament, the recognition of the authoritative writings:
We have The New Testament as a Witness (circa 50-100 AD):
Another passage (Mt 23:35; compare Lu 11:51) seems to point to the final order and arrangement of the books in the Old Testament canon. It reads: "That upon you may come all the righteous blood shed on the earth, from the blood of Abel the righteous unto the blood of Zachariah son of Barachiah, whom ye slew between the sanctuary and the altar." Now, in order to grasp the bearing of this verse upon the matter in hand, it must be remembered that in the modern arrangement of the Old Testament books in Hebrew, Chronicles stands last; and that the murder of Zachariah is the last recorded instance in this arrangement, being found in 2Ch 24:20,21. But this murder took place under Joash king of Judah, in the 9th century BC. There is another which is chronologically later, namely, that of Uriah son of Shemaiah who was murdered in Jehoiakim's reign in the 7th century BC (Jer 26:23). Accordingly, the argument is this, unless Ch already stood last in Christ's Old Testament, why did He not say, "from the blood of Abel unto the blood of Uriah"? He would then have been speaking chronologically and would have included all the martyrs whose martyrdom is recorded in the Old Testament. But He rather says, "from the blood of Abel unto the blood of Zachariah," as though He were including the whole range of Old Testament Scripture, just as we would say "from Genesis to Malachi." Hence, it is inferred, with some degree of justification also, that Chronicles stood in Christ's time, as it does today in the Hebrew Bible of the Massorets, the last book of an already closed canon. Of course, in answer to this, there is the possible objection that in those early days the Scriptures were still written by the Jews on separate rolls.
Another ground for thinking that the Old Testament canon was closed before the New Testament was written is the numerous citations made in the New Testament from the Old Testament. Every book is quoted except Esther, Ecclesiastes, Canticles, Ezra, Nehemiah, Obadiah, Nahum, and Zephaniah. But these exceptions are not serious. The Twelve Minor Prophets were always treated by the Jews en bloc as one canonical work; hence, if one of the twelve were quoted all were recognized. And the fact that 2Ch 24:20,21 is quoted in Mt 23:35 and Lu 11:51 presupposes also the canonicity of Ezra-Nehemiah, as originally these books were one with Chronicles, though they may possibly have already been divided in Jesus' day. As for Esther, Ecclesiastes, and Canticles, it is easy to see why they are not quoted: they probably failed to furnish New Testament writers material for quotation. The New Testament writers simply had no occasion to make citations from them. What is much more noteworthy, they never quote from the Apocryphal books, though they show an acquaintance with them. Professor Gigot, one of the greatest of Roman Catholic authorities, frankly admits this. In his General Introduction to the Study of the Scriptures, 43, he says: "They never quote them explicitly, it is true, but time and again they borrow expressions and ideas from them." As a matter of fact, New Testament writers felt free to quote from any source; for example, Paul on Mars' Hill cites to the learned Athenians an astronomical work of the Stoic Aratus of Cilicia, or perhaps from a Hymn to Jupiter by Cleanthes of Lycia, when he says, "For we are also his off-spring" (Ac 17:28). And Jude 1:14,15 almost undeniably quotes from Enoch (1:9; 60:8)-a work which is not recognized as canonical by any except the church of Abyssinia. But in any case, the mere quoting of a book does not canonize it; nor, on the other hand, does failure to quote a book exclude it. Quotation does not necessarily imply sanction; no more than reference to contemporary literature is incompatible with strict views of the canon. Everything depends upon the manner in which the quotation is made. In no case is an Apocryphal book cited by New Testament authors as "Scripture," or as the work of the Holy Spirit. And the force of this statement is not weakened by the fact that the authors of New Testament writings cited the Septuagint instead of the original Hebrew; for, "they are responsible only for the inherent truthfulness of each passage in the form which they actually adopt" (Green, Canon, 145). As a witness, therefore, the New Testament is of paramount importance. For, though it nowhere tells us the exact number of books contained in the Old Testament canon, it gives abundant evidence of the existence already in the 1st century AD of a definite and fixed canon. (https://www.blueletterbible.org/search/Dictionary/viewTopic.cfm?topic=IT0001836)
Again, my contention remains that there was no legitimate reason for the Jewish religious leaders to exclude the Deuterocanonical/Apocryphal books from their recognized writings from God. Unto them were given the "oracles of God", St. Paul said, they would not have discarded them as canonical if they truly were no matter when an "official" canon was compiled.
I said very clearly The Jewish canon closed AFTER
and you then say Is it your contention that the Jewish people didn't have any idea what writings came from God and were authoritative prior to that time
Just as Christian canon was closed in the 300s, but the majority of books were known as canon, you had the same with the Jewish canon -- the first five books were canon and so were the historical books, but then from the prophets onwards there was contention.
Why do you think that the Samaritans have a different canon?
He very clearly is referring to specific books, not defining canon.
Jesus also quotes from Sirach btw.
There was a legitimate reason to do so after the destruction of the second temple - in fact two legitimate reasons:
To survive it was necessary to expunge works that would give the heretics (Christians) justification.
In other words, did the Jews of the first century A.D. who had rejected Jesus Christ and the entire New Testament no long have the same authority as the Jews of the second century B.C. who used the Septuagint? Yes, I think that would be an accurate statement. I would also remind you that the present Masoretic text used by the Jews today only goes back to the 7th - 10th centuries. Among the Dead Sea Scrolls are Hebrew texts of the Old Testament that differ from this and match the reading of the Septuagint.