Perhaps some of his other stuff isn't great either, but not everything is equally problematic. I would argue that this video is the worst of them all.
We tend to allow our children to watch Jewish videos freely. Unfortunately today more than ever we must ascertain if what they are watching is truly "Jewish".
Putting aside the content of this particular video, I think that your suggestion and logic is flawed. No one ever gave Meir Key a hashgacha. He never once made a claim that everything he does is approved by the beis din in crown heights or anywhere else. You anger is that you allowed yourself to consider Meir Kay Kosher, and he turned out a "Traif" video, destroying your trust.
Clearly Meir has been putting out content similar (albeit minus the gay couple part) for years. He's also been invited to the Kinus, and to do the Kosher Superbowl halftime show with Nachum Segal. If others think like you, he may not be invited back.
But the moral of this story is - if you're concerned about what your kids are watching, you probably need to do a better job of monitoring them.