Another not needed article that already disqualifies itself with the main header. The author makes the mistake of so many others that confuse the OOP paradigm with the concept of classes. OOP does not need the latter. Class support is not even a criteria which qualifies a PL as OO. A lot of experts would even argue neither is inheritance, but code re-use is. Anyhow, code-reuse (and/or inheritance), encapsulation and polymorphism are all achievable without the class concept.

Thus, answering the OP's question within the context of examining multiparadigmatic and OO supporting PL's like Rust and Go ...

No, OOP is not dead. But the over-usage of classes and inheritance for modeling type systems/hierarchies might be on the decline whereas Trait and/or Mixin based composition techniques hopefully might get more attention/recognition.