For now. Did you know at one time Air Wisconsin was the largest United Express at one time, they even had 70 plus seat jets. I'm talking the 90's. Remember West Air? Probably not, they were a huge west coast feeder for UAL. Britt? Bar Harbor? Presidential? These were all big regional airlines that have come and gone while providing "feed" for UAL and CAL. Where are they now? Gone via buyouts, closed doors, etc.
Will the large number of RJs disappear overnight? Not likely. They didn't show up overnight. They are the product of massive givebacks and concessionary agreements. Will the numbers be capped, and contracts allowed to expire with not allowing replacements. Much more likely. Will there be winners and losers in the the regional feed for the new UAL? There most certainly will. Regionals are pawns in the Mainline game. Management know this. In fact, they love it. They can whipsaw entire airlines against each other. I'm not ragging on the regional airline pilot. I flew 9 years at one. The solution? Get mainline flying back where it belongs.........to mainline.
I watch in disgust the numbers of 70 seaters flying around that once were very good mainline jobs, Do I hold disdain for the pilots? No. They're just flying the best equipment their airline has to offer. If you fly for a regional airline, you are an outsource provider who can be replaced at the end of the contract, sometimes even before. That is reality.