Most C++ developers won't easily develop systems in Rust because of lack of well-known libraries and a stable ecosystem(profilers, static analyzers, concurrency tools, many skilled and mediocre developers, etc). C++11 and subsequent versions have a good amount of memory safety(though not as safe as Rust).

Rust is a modern language with very good concepts and features. It's quite complicated to learn.

My answer is it will be a good language, but won't be a top language.