Yeah C++ isnt going away anytime soon - its not even in the COBOL phase of its lifetime despite the rise of Rust/Go as systems languages.
However it would be imperative for a push such as Carbon[1] to be similar to the kotlin to Java. A modernisation that simplifies , maintains backwards/forwards compatibility and reuses established libraries and tooling.
This however will need a entity that can champion and push it forward with a strong enough project to anchor it in the mainstream.The transitions are doable ,like Android dev from plain java to kotlin , or in OSX moving from Objective-C to Swift.
Additionally borrowing a robust batteries type standard library to reduce the sprawl of coding options and funnel greenfield projects into best practices and less boilerplate.
[1] https://www.infoworld.com/article/2337225/beyond-c-the-promi...