And apparently it was enough for the Secretary of State's people to see, too.
Now it's important to note the context of the source. The diplomatic cables are--effectively--gossip reports. In general, they're not indications that anyone actually believes them, nor indications that their reports are causes for action. A report that a French president is concerned about threats to French suzerainty in its former African colonies is exactly the sort of thing that I'd go "right, I believe that... and I don't care." There is yet, to my knowledge, any evidence that this actually influenced US foreign policy in any manner whatsoever, let alone supports the petrodollar-supremacy narrative.
Why the US and the West targeted an anti-Western, terrorism exporting dictatorial regime with a history of trying to acquire WMD whose overt ideology was a blend of totalitarian socialism and a unique version/descendant of Islam during a period where it was unusually active in targeting anti-Western, Islamic regimes especially those with a history of trying to acquire WMDs under the aegis of a war on terror?
Dunno. Must be rumors that they planning to move away from the CFA Franc somehow raising worries that they’d stop selling oil for dollars.
Source? Specifically, a source that can pinpoint a statement by a Libyan official in the immediate run-up to the intervention in Libya (i.e., late 2010 or early 2011) indicating a desire to switch to selling oil in euros.
The closest I've ever seen to such a source is that one of the cables released in the Wikileaks leak reported that a source close to Sarkozy outlined a few reasons why he wanted to intervene of Libya, one of which was a desire to replace the CFA franc (effectively backed by France) with a gold-based Libyan dinar.