Why don't you do online check-in 24 hours before then you choose your seats and it's free to do so.
Thats good in theory but in practice, after the latest 'change' to the seating policy, is as much good as a chocolate fireguard.
You've missed the key point though - it wasn't a case of him wanting to sit next to his wife, it was a case of
needing to be sat next to his wife for medical reasons...