Don't know what to make of this kind of situation but I am not sure one can generalize as far as ABCs are concerned.
My employer (100,000+ employees) is actually big on diversity, i.e. they have a fairly large number of African Americans, Latinos, and white women in VP/SVP ranks and a few Indians got into SVP positions recently. The issue with East Asians (Chinese, Koreans etc.) here appears to be the lack of depth among the mid and senior managers.Currently there are a small handful of Chinese on the VP level, and none of us are ABCs. Instead, we were all late/mid-80's graduates from Qinghua or Beida - it's kind of hard to break through the rigid corporate hierarchy in a large American conglomerate for a 1st generation immigrant from China, regardless how technically qualified he/she is otherwise. We are simply not as strong in some of the "soft" skills as our American collegues, and cannot build as many useful social connections and networks, if we are not familiar with rules and lores of baseball and football, cannot recall scenes in old cult movies and call out facts about the 80's rock bands. Heck, we actually read Chinese websites like "wenwuecity" and watch CCTV for entertainment. That said, I am at peace with where I am and who I am, and it is what it is.
Regarding ABCs, I have yet to meet one that is Ivy educated and has the drive and experience to break into the junior executive level, let alone the senior and C-level leadership in my company. However the dearth of promising ABCs might be specific to our industry today and things will get better. I am hopeful about the prospects of my kids' generation.. When it comes to climbing the corporate ladder, I personally believe an Ivy education (also as a selection process) would help, as opposed to hinder their progress.