I was looking into a framework laptop and noticed 2 things.
1: The 13" has no linux keyboard.
2: The spacers on the 16". If you order only a keyboard you need 4 spacers. Why not make a long spacer (1x2)? I have read the thread about the trackpad with spacers included. But this solution still leaves room to switch the spacers.
The only difference is that the linux keyboard doesn’t have a windows logo on the super/meta key. All keyboards are still functional in linux.
As RandomRanger said, this allows Framework to allow for more freedom to customize your keyboard and trackpad locations without making more SKUs. They are still a relatively small company and do this to keep their logistics manageable.