The Major Airlines that want to save the regionals will end up just creating ab-initio. Some have already started this process like United and their Aviate Academy. The one missing link is who is paying for training.
It’s not hard to see a future where United (or insert airline) pays for all or most of your training. Maybe students have to show up with a PPL, but United pays for the rest. You then instruct at their Academy until hitting the ATP mins, then go to the regional of their choice where you are contracted for 5-7 years before you can move up to the big boys.
That would solve their staffing problems, but the cost of paying for initial training is a huge hurdle that hasn’t really been necessary in this country yet. It will be interesting to see what plays out.