I also have a Europe 1 itinerary booked pre December 15. Earlier this month I called and made changes to dates and cities. All I was charged is the change fee and a bit of extra tax. No extra miles. My city changes were my destination (still Europe 1) and the connecting city on my return to NA.

If I remember correctly I had called AE a few times prior to December 15 and talked to 3 different agents about making changes (not including zone or class changes). 2 of them said there would be no extra miles while the other said extra miles would be required.