OO is defined by message passing. What does a closure have to do with message passing?
OOP is defined by encapsulation and subtyping (polymorphism and inheritance). In fact, the one thing that doesn’t exist in standard FP is inheritance. (Encapsulation sort-of exists with closures, and polymorphism exists with function values.)
Having objects does not make a language oriented to those objects. By your definition C++ would be considered OO, but we know it is not. Kay quite explicitly stated that C++ is not OO. I expect you're thinking of Object-based programming.
If you look at the actual definition of OO, it basically is just a laundry list of Smalltalk features. It is probably not usable outside of Smalltalk for that reason, despite Joe Armstrong's playful insistence that Erlang is the only OO language in existence.
You might be able to include Ruby and Objective-C (and, iff you're really stretching, Swift with @objc enabled), but that's about the extent of it.
Object-based means OO without inheritance or subtyping.
Simula has objects, but that does not imply that the objects are oriented.
