My take? He is having QA problems with the side panels at the hole size & pattern that he is aiming for; delays with I/O and other problems with colours. And thus a base model with mesh, in black, and without I/O.^ This.
Mesh is great – for filtering. As rendered above the Sidearm is now just a frame with screen doors. I choose to put components into a case for protection and noise isolation; it appears the base model will accomplish neither well.
What's going on, is the CNC making it difficult to hit the price point? Put me down as waiting for real side panels, thanks.