In "jokes", people often state propositions that seem opposed to what we would hope they believe.
In any case, the above fails the first rule of jokes... they're supposed to be funny. I thought the post was funny enough. But the reference to a co-prosperity system didn't add much (any?) humor to it. Just pointing that out to the OP...
Repurposing the stilted propaganda of long-ago times, or of clumsy tyrants, for subtly absurdist/ironic humor value, does not in any way lessen the original horrors. It celebrates the distance we've achieved, while also offering a teaching moment by contrast/reference.
See also: "we will bury you", "let a thousand flowers bloom", "we had to destroy the village in order to save it", "i have in my hands a list of hundreds of known Communists", "the war to end all wars", "the mother of all battles", "this blogger has been harmonized", etc.
Personally I thought the co-prosperity added to the humour with an over-the-top name, and I detected a slight whiff of Eastern Bloc over-the-top naming, akin to Council for Mutual Economic Assistance or Polish–Soviet Friendship Society. But then my ethnic background is Polish and not an East/Southeast Asian one.