Another test. Used the Netherlands in 1700 because it was a good variety of owned provinces. I bankrupted then looked around at various provinces. No RR factors were doubled except for WE. (I did not check all of them, i.e. no event-caused ones, but did check rebels, tax collector and judge, stability, culture, and manufactory.)
Then I imposed war taxes, and got unexpected results. The +1 from war taxes was doubled, but the WE doubling stopped. I waited out the 6 months of war taxes, thinking that the double WE would return, but it did not.
Incidentally, the dialog for Bankrupcy actually does say that war exhaustion is doubled. Never noticed that before.