I'm going to bet on commutair, xjt, and air whisky closing shop and furloughing all employees. Republic and Skywest will furlough a large percentage of their force.
This will be at the same time the major airlines furlough 2-3k pilots each as well.
Furloughs called back to the majors by 2024-2025. Hiring beginning then as well from existing regional airlines. Current XJT and C5 pilots will not have any flying opportunities until Skywest, Republic, Mesa, etc a) recall all their furloughed employees and b) lose enough employees to attrition from major airline hiring.
So, probably 7-8 years.
This is all just a WAG.