Perhaps a subtle change, but 3.5 of the previous T&Cs stated that "Once the ticket has been issued, a
Member may, subject to conditions, change or cancel his Reward ticket prior to departure
of the first flight segment and shall do so in accordance with the procedures as set forth in
Flying Blue Communication"

New 3.2.8 clarifies that changes are accomplished via the cancellation of the old ticket, and the sale of a new one. (Note - this of itself does NOT mean that reward tickets are all cancellable for free).

I may be wrong, but my understanding was that "changes" to tickets were effected in this manner anyway.