Nonsense. Sometimes the last seat they hold back but the others are always available
Did you actually check that out?
Try calling EY to see seats, or check expertflyer, you'll see most flights they release 9 seats for awards. Vs. AA, on most of the same flights, they'll offer you 1 or 0 seats.
This is based on my experience. I'm open to change my mind, if someone can show me the same 9 seats will be available by AA...