If they recanted on the CR1's (which affect a much smaller segment of the flyer community), I really doubt they'll cancel E+ which would have a hugely negative impact on a much larger segment. At least, I sure hope so
Now this is the thing I fear the most: if the new CO/UA scales back the number of flights, then there will be more elites with fewer flights/seats to choose from. UA is already elite-heavy, and now they have yet another tier (the 75K tier from CO), that just screws everything up even more.
Just today I was on my way back from asia (return leg from a DEN-SFO-HKG-TPE-NRT-SFO-DEN in C), and the 777 (UA862 for the SFO-DEN leg) F was completely full of nothing but GS + 1K's. Of course, the meals were not available for everyone, and I overheard the FA telling a 1K sitting near me that everyone in F was top-tier when the 1K complained that she was a 1K and asked why she couldn't get her selection. That is on a 777 with 36 F seats, nothing but GS+1K (who knows how many were in back)! I can't imagine that getting any better, especially when CO/UA start scaling back flights which is what I expect to happen as they consolidate routes.
As an EXP, I've never had this problem, and I've only had to go back past row 6 on the MD-80 once this year, and that's when I booked my flight one day in advance.
The one thing missing from UA/*A and would put a pretty big nail in the AA coffin (for me, anyway) would be if *A added another tier that gave the equivalent benefits of OW Emerald. That's a big deal for international travelers (FC lounge access, FC check-in, regardless of ticket class, etc). If I, as a 1K, could get equivalent OW benefits + *A routing + E+, heck, I'd be UA forever and never look back. That'd make up for the times when my domestic UG didn't clear, because honestly, E+ and drink chits is darn near the same as F unless you're flying transcon