Thanks all. After giving this thread a read I have a much better understanding now. How this caught my attention was that when I did OLCI at T-24, I noticed that many seats were shown as occupied. I checked on EF and most of those seats were shown as blocked. A few hours later, I noticed that some blocked seats opened up.

A few years ago a client of mine was working on a feature to show different seat maps to different passengers. The algorithm was basically showing X empty seats among a set of seats Y, where X and Y depends on passenger's status, fare, aircraft type, etc. Y can be defined by things like row numbers, last X rows, window/middle/aisle seats, or just a list of seat numbers. I even wrote a few test cases testing this feature on a hypothetical 3 class B773.