Expanded Universe

Is the expanded universe cannon because I was reading the page about >!Szayelaporro Granz!< and it seems to contradict what was established in the Manga/ Anime If He was the >!cero espada and then he removed his brother from him and from what I understand he became an adjuchas again wouldnt that mean he became an arrancar before Yylfordt Granz.!<Idk it just seems kinda confusing to me