I'm mid-list (1500ish) and I think I would have to wait out 5 years of constant hiring to move to mainline via this agreement. I think at 2400 you're looking at closer to ten. Of course attrition to other places will change that some, as would any slowing of hiring at AA.
IOW, this is not really a consideration for a newhire anyway. Come to Eagle, get some good training and work with good folks in a decent operation, but keep your resume up to date if this isn't your dream job. Of course, they could work a new agreement to entice more newhires, that wouldn't surprise me at all. Unfortunately the only value is in an actual number on the mainline list (as opposed to a pref hiring promise), and that's pretty unlikely IMO.