I very much hope that this is not what happens, i.e. that we aren't all given a new membership year based on the arbitrary date Accor picked to implement their rule change.

There's also the question of how long points take to post and how that will affect people who complete stays in the week or so preceding the change.

I suppose it's possible that Accor has thought this through. In that case it would be very nice if they would communicate their thinking to their CdA members.