Did you notice that the other thread you casually replied in was almost a year old?
Have you checked Preferences > Type > Type Options: Use Typographer's Quotes?
Though honestly, I would think that InDesign has no place converting quotes on XML important, so perhaps there was a behavior change. ID imports what you tell it to do, so if you want curly-quotes in imported file, you should give it curly quotes on input. XML is all about being in control, and that means ID has to do what the XML tells it to do. Still, try the preference?