Your requirement of a USB Aport to satisfy an esoteric accessory is a niche use case. They are not going to include A USB A just like why they won’t add a firewire port to satisfy that 1%.

Pretty much all new keyboards, even niche ones, now come with Type C standard. Plus you are making a huge deal out of the graceful degradation of attaching an adapter to your keyboard. If we’re going to permanently retrofit something its going to be your keyboard—not the macbook.

I upgrade my gear regularly. And because of that I pretty much never use USB A. Apple designs their products for people who upgrade their gear. If they add a USB A to my shiny new laptop it’d be quite annoying because it is 1 extra port that I will never use that is probably there at the expense of another Type C port.