fat binaries (or whatever)?

[Patrix]

I was about to show the concept to a friend of mine and I had a big
surprise when the feature was gone lol.

When last I used gnustep a year or two ago, a .app had a directory
structure inside relating to operating system, display backend, etc,
and finally a binary. This was to allow fat binaries or whatever they
call them, that could run the same .app on multiple OSes, if I
remember correctly. Now the binary just sits at whatever.app/whatever.
Is there a reason for this?