Wow... I was really surprised by this video, so I did a quick search. It is not a school play, but rather professionally done to mimic a school play. There is a little relief in that fact.
It's not a terrible thing in my book. It wasn't a school play, there was parental permission, and young kids are often part of racy movies. It's not like little kids don't point stuff at each other and shout "BLAM BLAM YOU'RE DEAD" on a daily basis, or don't constantly hear worse language from Youtube, their friends, and sometimes their parents.
Professional job or not, parental permission or not, I find it reprehensible that adults would put kids up to this. It just makes me wanna shake my head and wonder what the world is coming to.