Sort of OT : SPG points to BA Avios.. how long?
Doing more research, it appears that seats open up more rapidly as the flight date approaches, as long as remaining inventory exists.
Also, my assumption is that if the J-R seat buckets show 9, then upgrades are more likely to be available since this is the maximum number of unsold seats in CW. WET bucket is for WT+ seats, which if showing say 000 for availability would mean that you might be upgraded to CW for free, if the flight is oversold and you are either Emerald or Sapphire and WT is oversold.