A 2.4GHz wave has a wavelength of ~12mm. The concept of blocking the emissions of a microwave oven is to only have small gaps, much smaller than the wavelength, in the metal casing. That's why you can have those 1-2mm holes in the door window without having much leakage; the holes are much smaller than the waves.

So as long as the gaps on the doors and panels of the microwave are still aligned right and the door closes somewhat tight (only a couple of mm gap) you're still trapping the extreme majority of the energy in the box.