He essentially got banned for either boss farming, chest farming, or using a storm ult glitch (which he forwarded to the devs on twitter) thats existed in the game since beta.
These farming routes have existed forever in games such as Diablo, Destiny, and tons of other MMOs. Being banned for playing the game efficiently is pretty harsh.
Not to mention..banned in a game thats purely PVE with no economy or PVP.
The top comment on youtube pretty much sums it up:
"Uses exploit in anthem - FOREVER BANNED
Uses exploit in destiny - bungie laughs, fixes it and makes it a meme Easter egg "