First off, saying the military "pays for your training" is misleading. They aren't paying you for your training. They are simply paying you to do your job, and learning to fly is part of that. They have plenty of guys go through training who have thousands of hours, they don't skip the training. It just not analogous.

I highly doubt that DAL/AA/UAL/SWA/FDX/UPS will ever pay for a training. If it ever does come down to ab-initio hiring (god I hope it doesn't), the candidate will pay for it. This is what jetBlue's program looks like and how it works in many parts of Europe. Or you might see the majors fund the training, but the candidate will sign a contract to fly for a wholly owned regional for 5 years and the company will deduct the cost from their paycheck until it is paid in full. If one quits, they will owe the entire amount plus 18% interest or something. This will be an additional revenue stream for the company. Kind of like how a car dealer makes most of its money off of financing.

Additionally, in five to ten years, there will still be lots of talent available at regionals, LCC's and from the military. With the recent uptick in salaries, young adults will again start flocking to the career like in the 90's, it just takes time.