Someone on 4chan translated it:
Report: spoilers from Nier Concert at Osaka. Once pod 153 detects that 9S has acquired classified information she reports the fact to 2E who then executes her mission. 9S, who finds out that 2B is actually 2E and that 2B is extremely pained by this repeated murder, commits suicide by logic virus. [Please continue killing me from now on]
Or more correctly [2B, please. From now on (possibly: from now on too) make sure to properly kill me.] 2B in response to that [9S, forgive... me.]
Because the logic virus was self-administered, 9S's body rapidly disintegrated starting from the head, hands and legs. Her words did not reach him.
That was the last time. Before that was also a time when 2B, after having killed 9S, wondered why he didn't resist. Pod 153 told her that [9S knew everything].
(9S's memories before getting killed were of the day the two were chased by a boar and defeated it, or of that time when they spent the whole day peacefully fishing in the Flooded City)
Also there was a time after the shopping mall, when 9S said [Let's go window-shopping when the war is over!].
9S was aware that he [Had special feelings towards 2B].
Pod 153 said to 2B who was in pain and anguish [Having emotions is forbidden].
Pod 153 said that 2B was created in imitation of a single prototype android who survived the Pearl Harbor Descent. Due to the prototype's excellent ability to operate in stressful situations, 2B was designated E. 2E said [I'm not... suited... to something like that] very very sadly.
In the end of the Prologue, right after the murder, 2E hesitates to delete 9S's memory data and reinstall preset personality. Pod 153 asks her why she does not execute her mission. 2B answers [You will not understand. I don't understand either]
9S said "2B is the light"
Until the plot of the game, the story was caught in an extremely sad spiral of life and death.
The performance itself followed the general flow of several songs being performed, reading of a play, another couple of songs, another play. Like in the game plot, each time 9S has actively approached 2B, the distance between them shrank, but the end was the same - murder.
We didn't get the actual script of the plays, so if there are mistakes - please forgive me.
There will be a performance the last day of the concert that takes place after ending E where 2B is trying her best to get 9S to wake up.
Edit:
Even more info:
It seems that 2B and 9S fought A2 a couple of times already. In pic related A2 says this is the forth time she's fighting 9S (and she seems OP as fuck).
There will also be 3 performances other than the E ending one:
5/4 - About Project YoRHa with new characters only
5/4 - Mainly about A2 and the times she fought and killed 2B and 9S
5/5 the story above from 9S' perspective, as well as going deeper into what he was going through in route C because they felt his contamination wasn't really well depicted in the game