This seems like a fig leaf, because Facebook has no authority or ability to fully inspect all of Cambridge Analytica's facilities and data throughout the world. There certainly won't be a police raid in London to seize hard drives or anything like that. And short of that kind of intervention by the authorities, we'll never know what Cambridge Analytica has or had.
I agree with almost everything you said, minus the raid in London. It won’t be FB kicking it off, but the ICO and Electoral Commissions in the UK are already investigating them, as is the EU, and in the USA, the Massachusetts AG.
Raids are possible, but it won’t be because Zucky boy and his motley crew did a thing.
Is this before or after the UK serves their warrants for the contents of CA's servers?