The West doesn’t actually want a destabilized Russian Federation. Could you imagine a rabid dog like Prigozhin in possession of nuclear weapons?
In terms of US agencies expecting it, yeah anyone following exploits of Prigozhin could see there was a probability of something like this happening. It was only somewhat surprising, but a scenario that’s been considered.
I think the stance on Putin and the Russian Federation is like Batman’s stance on Ra’s al Ghul. “I’m not going to kill you, but I don’t have to save you either.”
A coup on Putin may result in the collapse of the Russian Federation just as the coup on Gorbachev resulted in the collapse of the Soviet Union. While a collapse of the Russian Federation isn’t really in the best interests of the West (because keeping nukes under one roof is preferable) at this point Putin is proliferating nukes to Belarus, and it seems Russia is just behaving in a self destructive way in general. We’re at a point where trying to prop up the Russian Federation for the sake of nuclear security may not be worth it anymore. It may not even be possible.
At any rate It’s very doubtful the CIA or any other Western intelligence agency had a hand in this. Ukrainian intelligence is possible. Given Ukraine is under threat of nuclear attack anyway, the’ye more willing to gamble. If this were the case Western intelligence probably were aware and just let it happen.