I have never seen Emirates exit row seats available online (though this may have something to do with only being a bottom level FF). I've just flown four sectors with them in the last three weeks, and 3 of them had emergency exit row seats available on the day.
Can anyone confirm whether they are available to higher FF statuses to book online, or whether they are allocated at check in to avoid having inappropriate passengers sitting there?
Always worth checking in early and asking... (which was how I found myself on an exit row three weeks back)