Did the Messenger not know of the Jews' fasting of 'Ashura' except in his last year, as he said, "If I live until next year, I shall fast the ninth"?

The Messenger of Allah, peace and blessings be upon him, fasted Ashura in the first year he arrived in Medina and continued to do so. Then, towards the end of his life, he intended to differ from the Jews by fasting the ninth day along with the tenth, and the hadiths indicate this.

On the authority of Ibn Abbas, may Allah be pleased with him, he said: (The Prophet, peace and blessings be upon him, arrived in Medina and saw the Jews fasting the day of Ashura. He asked: “What is this?” They said: “This is a righteous day; this is a day on which Allah saved the Children of Israel from their enemy, so Musa fasted it.” He said: “I am more deserving of Musa than you.” So, he fasted it and commanded its fasting.)

On the authority of Ibn Abbas, may Allah be pleased with both of them, he also said: (When the Messenger of Allah, peace and blessings be upon him, fasted the day of Ashura and commanded its fasting, they said: “O Messenger of Allah, indeed it is a day that the Jews and Christians revere.” The Messenger of Allah, peace and blessings be upon him, said: “If it is next year, Allah willing, we will fast the ninth day.” He said: “The next year did not come until the Messenger of Allah, peace and blessings be upon him, passed away.”)

Ibn Al-Qayyim said: “And this indicates that his fasting of it and his command for its fasting was one year before his death, while his previous hadith (definition) indicates that this was upon his arrival in Medina.” He also said concerning the second hadith of Ibn Abbas: “There is no doubt that this was in the latter part of the matter, whereas in the beginning, he loved to agree with the People of the Book in matters where he was not commanded otherwise.” And Shaykh al-Islam Ibn Taymiyyah said: “Then, when he was told shortly before his death that it was a day revered by the Jews and Christians, he commanded opposing them by adding another day to it and resolved to do so…”