It's complicated, but you have to look at "regional flying" in terms of capacity to generate revenue, not airplanes or seats. Seats is a closer approximation but is still not accurate because mainline aircraft seats are more fuel efficient, and mainline aircraft carry significant revenue cargo while RJ's carry almost none.

POTENTIAL Pilot compensation is always linked ultimately to the revenue generation capacity of the aircraft.

You'd have to do the math but it's safe to assume that regional flying is not really shrinking in terms of revenue. The 50 seaters are not making money with current fuel prices, so they had to go. As much as ALPA would like to claim a scope victory for the 50-seat drawdown, that had nothing to do with scope...it was all about revenue or lack thereof. Management just gave away something they were going to get rid of anyway. There may have been a scope victory in preventing one-for-one replacement with 90's.

A shift of capacity to larger aircraft will mean fewer regional jobs, but necessarily more major jobs.

A true scope victory would require moving the 90's (anything with more than 79 seats or a certain max weight) to mainline.