Inheritance is not a must have in OOP, as plenty of SIGPLAN and ECOOPs conference procedings report.
So yes their style can in certain cases be called OOP.
Just like being a multi-paradigm language, with support for OOP, doesn't magically make it non-OOP.
Anders, Goetz, and Torgensen on recent years have all talked about the need to add functional features into the languages that started as OOP (and is what they have been doing with C#, TypeScript, and Java since 1.6 or so). One also suspects they made them OOP because they did them on comission and the goal (of Sun, MS, etc.) was to attract devs with what was considered hot at the time...
But neither Rust nor Julia support inheritance, so if their style can even be called OOP, it's not the OOP of the kind that Joe talked about where you "get a gorilla holding the banana and the entire jungle", and which most devs know from C++, Java, and yes, Python and Ruby.