I could be mistaken, but the only pilot reductions that I have herd mentioned at JAL was putting an end to the over 60 guys continuing to fly. I have not herd of any of their regular pilot ranks being reduced. Please correct me if I am wrong. Most of the other non pilot reductions will come from retirements that will not be replaced with new workers. Again, from what I have read.
JAL will not go out of business. Who is there to pick up the slack? ANA is probably about 1/2 to 1/3 of the size of JAL and could never come close to picking up the slack. Whether it is the government or a foreign investor, someone will dump their money into JAL to save them.
Regarding the pool. I don't think anyone knows the numbers. Entry into the "pool" is not a guarantee of a job offer in the future. From time to time, the "pool" is drained of the lower scoring individuals.