Viable and fun end-game really early on. I know basically everyone is trashing the idea of PvP, but one thing PvP can contribute is some sort of end-game. There are certainly PvE-only games that have excellent end-games (e.g., D3, PoE), but slightly worries me that we have already played 33% of the strongholds that will be available at launch.

I know they have mentioned plans for aspirational content down the road, but the looter-shooter genre relies on early momentum to survive and really thrive. You don't have to look farther than Division (which ironically had PvP) to see what happens when you don't have enough content at launch. Even though they had a ton of awesome stuff to do at 1.8, the player-base never really recovered. Perhaps one counterpoint is Destiny 1, which was also content-starved early on but thrived as more end-game activity arrived. Some confounding factors include PvP and lack of competition within the same genre at release.