Yea that's a little shocking. I know they've omitted Angel of Death a few times but they've always played Raining Blood and all four members have stated its their favorite song to play live.
Maybe they were told they needed to cut their set short mid set and just thought fast.
I listened to three Babymetal tracks...sounds like Chun Li getting butt-fucked by Andrew W.K. That's not something I ever wanted to hear.