which is exactly what happens
but it is wrong not to gain any vertical FOV as you approach square monitors !
why ? So everyone sees the same size area irrespective of ratio ? That would mean that the wider your monitor the less you would see ahead, which is awful.
As it is everyone sees ahead by the same amount but less on the sides, which makes a lot more sense given that you are usually walking up / forward, not sideways or down / back
Game-play wise people with high quality 16:10 or 4:3 professional monitors will enjoy the game more since more vertical FOV will compensate some of the losses from less horizontal FOV.
and that is where you are wrong, more space on the sides does not compensate for loss at the top, as you are usually facing up
Vertical FOV is much more important than horizontal FOV, so you cannot increase horizontal to compensate for the loss of vertical FOV.