100+ reserves in CLT for June is more than enough. Currently FO spend two months after sims before starting IOE. Two months of no classes will get the footprint back on track.
When they start running new hire classes again, there should be very little time spent in between ground school, sims and IOE(this is good for new hires).
Upgrade classes are every two weeks. An upgrade class that goes unfilled with FOs will have street captains added in(in order to fill the class).