Imho, most features of Rust that people would like to see in Go would still fit into the "concept" of Go. Just like they added generics, they could add just three things: A generic container for errors (Result), one for saner Nil handling (Optional) and a small sprinkling of syntax sugar to make these comfortable to work with (something like an elvis operator equivalent).

Go has the one big advantage that is almost solely responsible for it's success: It was created and directly used by a giant company that could afford to create amazing tooling around it and develop great opensource libraries for it. Already being in use and having libraries feel like the biggest determinants of a languages success.