Ah, good question. Rust could definitely be in that list as well! It's a more mature language (so that's why I didn't mention it in the list), but conceptually it very much fits.
Seeing the original list, my guess was that it was no gc, with a small runtime - and the immediate question then was - how is this different/better than "D as a better C"?
The main difference is simplicity. D has a lof of features, like classes, inheritance, exceptions, properties, etc. Muon is a much simpler language that specifically avoids all of those things.