Way too much bezel. The last MBA hardware revision was what, 4 years ago? I'm sure they can cut it down more than that.
I am no Einstein but just some simple math:
Assume
-12.2 screen 16:10, width 10.2" (25.9cm)
-standard keyboard edge to edge, 11" (27.9cm)
Leaves 0.4" (1cm) for the bezel on left and right side. 'Way' less than on these renderings