https://wccftech.com/marvels-avengers-upcoming-hero-additions-revealed-through-datamine/

This past weekend, PC players had the chance to try Marvel's Avengers for the first time during the beta. As often is the case, some enterprising gamers were able to find ways to discover yet-to-be-announced things. For example, we got to check out the full breadth of the skill trees and skins for both Captain America and Thor.

Now, Reddit user '6plus4equals52' posted a list of unannounced hero additions that were found through datamining.