Originally Posted by eternaltransit

Do note that EK also restricts J inventory if they have overbooked Y as well (which on those routes, is likely).

If you are looking at a full seat map - then that means people have actively chosen/assigned those seats: EK doesn't block off the seats if unassigned, e.g. from travel agents, they are just left open, apart from exit-row seats, where you need to go to the airport early to get them.

In other words, whilst it's unlikely that a wide-open seat map means the flight will go relatively empty, if the seat map is full, it is highly likely to be that full.