As a data point, was charged Euro 300 at 19:15 as a change fee for moving a DEN-LHR-CDG flight forward a few days.
(Obviously won't be going to Paris this time!)
Thought I would just pay and argue case later, but now see I have some ammunition from the latest notice.
So for anyone else - if you see a change fee - just pay it and I'm sure you'll get it back later. Confirmation emails are time-stamped.