ARR: 10 jobs
HW: 13 jobs
SB: 15 jobs

Extreme Trials only drop 1 chest with 1 weapon in it. In ARR you had a 1/10 chance of getting the weapon you desired, in SB you have a 1/15 chance of seeing the weapon you desire. If the next expansion in 5.0 has 2 or 3 new jobs, we're looking at 1/17 or 1/18 chance of the weapon you need dropping. That said, I am suggesting SE make future Primals in the next expansion drop 2 chests.