I am also wondering if the quantitative proficiency thing is only completed for the obvious applicants: those that have 75% or above on the GMAT Quant. If this is the case, then it should NOT be an indication of potential rejection/waitlist vs acceptance.
In my case, I am 1 point short of the 2014 75percentile. So, in my case they would have to look through my transcripts, my justification in the supplemental essay, and my work experience before they can evaluate my quantitative proficiency. Maybe they are putting off evaluating applicants that are below 75%.