Without the ex-ATA aircraft, and to a small degree the conversion of East 757's to ETOPs, there would be even fewer 737 and up captain seats on the East side than currently exist. It's impossible to add aircraft, even to a shrinking fleet, without adding jobs to fly those aircraft - even if the added jobs merely slow the reduction in jobs. Take away the ex-ATA 737's and you'd have something like 370 or less 737 or better jobs today. So you can't say that additional aircraft don't create captain jobs (or F/O for that matter) - it's an impossibility unless the airline is overstaffed with captains enough to just absorb those jobs, and the overstaffing means more captain jobs than there should be to start with.
Would that have made the difference between you checking out or not? I have no idea. Would the Nic list being in effect have made the difference? Again, no idea. Both depend more on how the pilots above you bid than there being more pilots above you. Perhaps some of those East pilots above you would have bid PHX/LAS instead of CLT AB captain, letting you get it quicker. Perhaps West pilots would have bid CLT AB captain, making you wait longer. How it all shook out for you (or any other individual) is anybodies guess at this point.
Jim
Of course the ATA planes helped, I never said they didn't. What I said was that even with those new aircraft we have fewer total captain than we did in '04, so I couldn't have checked out without our attrition. It's pretty clear how things turned out. Those guys slotted into my class are even farther away from captain in PHX and LAS.