I am confused about the timeline in this game.

According to Niccolò Machiavelli's journal entry 1: "Although it was believed that the Assassin Brotherhood has abandoned Monteriggioni and the Villa Auditore was left for ruin; one Assassin was still acting as a guardian for the citizens and protector of the secret chambers under the city." This refers to the Siege of Monteriggioni in the beginning of Assassin's Creed: Brotherhood.

And entry 11: "I had a knock on my door from my good friend Ezio Auditore. Ezio was accompanied by his uncle Mario Auditore and one of the most valued ally of the Assassin Order, Leonardo da Vinci. They presented me with an ancient artifact that had 'magical' powers. It was decided there and then that me and Ezio should take it to Forlì and leave it in the hands of Caterina Sforza." This refers to the Assassin's Creed II DLC: Battle of Forlì.

The Niccolò Machiavelli's journal can be read right here: https://assassinscreed.fandom.com/wi...'s_journal

The Siege of Monteriggioni happened in 1500, and Battle of Forlì happened 1488. The Battle couldn't be after the Siege. And information from Assassin's Creed Wikia, the memory sequence Italy - A Murder of Crows was happening around 1502-1506, but I can't see the date in the game. Another in the game, Niccolò Machiavelli and Ezio Auditore's wearing in the memory sequence Forlì - A Crimson Sunset were from Assassin's Creed: Brotherhood.

Such of these, was Ubisoft created a non-cannon timeline?