With Fiji waiting (close?) to become a full Oneworld member (due April 1?) I'm wondering if it makes sense to book a RTW before joining. I would like to consciously choose the route via NAN, because it puts me in the more suitable, cheaper DGLOB34 fare. If I have to rebook after joining Oneworld and FJ is then a full member, would the DGLOB34 (if already booked) still be valid/possible/applicable despite the possibility of the ticket being re-issued or would I fall into the (in this specific case much more expensive) DONE4 or DONE5 fare?