We can't know for certain but I expect these were made available, but nobody chose them. The system was fair but in the end had an inherent randomness factor. People who originally bought first got to choose based on what was available. As later people picked, they might have abandoned seats that someone who selected earlier might have wanted. Too bad for them. It seems you could ask to be given a second opportunity but I doubt many bothered. Front row of section seats were highly valued, but it is possible that some were given up late in the process by people with different priorities, such as moving near friends, moving to supporters section, combining 2 sets of seats, etc. Then nobody saw them and now those are available to first time buyers.
Don't know if this means anything, but as a non-STH, I just received this email.
TBH, I wasn't going to reread all 7 pages to recall if anyone was interested, but new locations and front row seats (my bold) kind of sound like locations some guys may have had an interest in. Odd they open up these types of seats now rather than give STH a chance at them first.
oss.ticketmaster.com/aps/nycfc/EN/buy/details/16FS