From my experience, I had one reservation on hold, and the JAL Mileage Bank web site showed those flights available while it was on hold. When the reservation was ticketed, it was no longer showing. Perhaps JAL will show other flights on hold as being available.
The JAL Mileage Bank web site's search engine has a few bugs. JAL will show flight segments on one itinerary available (Flight CX 881 1st leg to Singapore, 12/18 for example), but will show the same flight (CX 881 1st leg to BKK, same date) as not available. Which is correct about flight CX 881? Maybe JAL could let us know which is correct.