If you prepped for NieR: Automata by reading wiki entries for Drakengard (which is in the same universe) and the previous NieR, you may not have even started the game yet -- that's how far the rabbit hole goes.
It's an insane series to say the least, so watching a one minute video narrated by the soothing voice of Automata's protagonist is probably the way to go here. Think Attack on Titan meets Shin Megami Tensei meets...Yoko Taro, and you'll have some sort of idea of where this clip will go.
Sure you aren't going to resonate with all of the emotional details as much as you would if you actually played the games, but the last 20 seconds or so should get you mostly up to speed with the intro of Automata, without providing any major spoilers for the even deeper rabbit hole you're about to descend into.
This really makes the case for Platinum handling a remake of every Drakengard and the original NieR.