Blaming the CIA instead of Belgium is a take. Belgian mercenaries working to support the would be Katangan regime did it, all so a Belgian mining conglomerate could get sweetheart deals. Because Leopold II was not an outlier.

The CIA was operating in the area, and there were plans, but they were caught flat-footed when Mobutu captured Lumumba, and then turned him over to Katangan forces.

Everyone was caught flat-footed again when Mobutu launched yet another coup and took power as dictator, but all the world's monsters quickly adapted.