The early steps into Anthem's future were laid out in a "gameplay calendar" breaking down the first act, Echos of Reality. According to its description, this trailer showcases your first story in Anthem, along with javelin personalization and a look at the expanding world of Anthem and its endgame content.
Once players have completed the campaign, they will be able to dig their teeth into Challenges, Contracts, Freeplay, and Strongholds, which will comprise a large part of Anthem's endgame. The second update, Stronger Together, will presumably focus on new co-op and social features - likely the guilds and leaderboards listed in the roadmap. One concern among gamers, pre- and post-demo, has been the length of the story mode and the quantity of endgame content.
Aside from those major points, Anthem's endgame is a lot of what's expected of it - contract missions, time-limited challenges (dailies, weeklies, monthlies), and free-roaming exploration. These world events cause physical changes to the world like extreme weather, deluges of hostile creatures, and changes to the landscape that will reveal new mysteries to solve. He described them as "content that you engage with for weeks", which would come out less frequently than new challenges, events, and strongholds.
Endgame features will be available once the player reaches level 30, the maximum level in the game. Then, Grandmaster 1, Grandmaster 2, and Grandmaster 3 difficulties can be accessed. Legendary contracts are larger, multi-part missions with bigger rewards.
Anthem's Game Director Jonathan Warner narrates the 5:30 minute video, guiding viewers through the various activities that will keep you employed as a freelancer. Improving your reputation with different groups will give you access to crafting blueprints.