I don't give much credence to new allegations. Where were these allegations when he was alive, and why are people still publishing documentaries? You don't need a documentary to make an allegation. They're doing it because they want to make money, then. Off a dead man, who can't defend himself.
It’s worth noting that it’s common for it to take years or decades for victims to speak out against an abuser. Especially when the victims are children. Especially when the abuser is a prominent figure, like the literal King of Pop.
I’m not going to try and convince you that these allegations are credible (though I believe they are), I just want you to think about how a child victim might behave in that situation. There’s almost never any objective evidence or 3rd party witnesses of abuse. It’s almost always the word of one person against another. And it may be years before a child victim even fully understands what was happening, and years beyond that to come to terms with it.