Google Updated the Help Doc for Discover to Reference E-A-Thttps://twitter.com
The help doc added the following new bit of information, it’s super generic and not something that you go action right way but apparently E-A-T might help with getting you content on Google Discover. Good luck.
Our automated systems surface content in Discover from sites that have many individual pages that demonstrate expertise, authoritativeness and trustworthiness (E-A-T). Those looking to improve E-A-T can consider some of the same questions we encourage site owners to consider for Search. While Search and Discover are different, the overall principles for E-A-T as it applies to content within them are similar.