The main sources for the more intricate parts of Aztec History are the writings of Chimalpahin, Fernando de Alva Ixtlixochitl, and to a lesser extent Fernando Tezozomoc. Also, Diego Duran wrote a detailed, although somewhat exaggerated, account of Aztec history. My question to you is, why would he be erased? Tlacaelel, alongside with his uncle Itzcoatl, was the mastermind behind the creation of the Triple Alliance that defeated the Tepanecs and catapulted the Mexica Tenochca to be the strongest force in central Mexico. First as Tlacochcalcatl, and then as Cihuacoatl, he always played a prominent role in Aztec politics. Now, in regard to Izcoatl burning of history episode, it is still debatable what he actually burned. For example, if you consider the event in its context, and the whole history leading up to the burning, it might be that what he burned was only the Tepanec libraries that connected the people of Atzcapotzalco with the Toltecs, since the Tepanecs were thought to have their origins near the valley of Toluca and might have been somehow connected with the falling Toltec polity.