Note: this is a legal question. Programmers.SE is not a legal forum, it's a programming forum. While the people here know quite a bit about programming, they don't know anything about the law. If you want to ask a legal question, you should ask that in a legal forum, where there are people who actually know something about the subject matter.
The GPL doesn't say anything about static or dynamic linking. It doesn't even say anything about linking at all. Every lawyer or judge I talked to says that the issue of static and dynamic linking is completely irrelevant.
Copyright is about creativity. Static vs. dynamic linking is a technical implementation detail. Whether or not something is statically or dynamically linked is not a creative act, it cannot possibly change the copyright status of a work.
In your question, you talk about "interpreted languages". But that term doesn't make sense: there is no such thing as an interpreted language. A language is an abstract set of mathematical rules and restrictions. A language isn't interpreted or compiled. A language just is. The term "interpreted language" is not just wrong, it is non-sensical. If English were a typed language, it would be a type error.
Interpretation and compilation are traits of the interpreter or compiler (duh!), not the language. Every language can be implemented with an interpreter, and every language can be implemented with a compiler. Most languages have both. Most modern language implementation even combine both in a single execution engine.
The Rubinius Ruby Implementation, for example, contains a static ahead-of-time compiler which compiles Ruby code to Rubinius byte code, an interpreter which interprets Rubinius byte code, and a dynamic just-in-time compiler which compiles Rubinius byte code to LLVM IR, which the LLVM infrastructure in turn compiles to native machine code. The MacRuby Ruby Implementation doesn't contain an interpreter at all, it compiles Ruby code straight to LLVM IR, then further to native machine code.
On the other hand, there are interpreters for C or C++.
All of this is just technical details. It is completely irrelevant to copyright.
It just doesn't make sense that whether or not someone violates someone else's copyright depends on whether or some third person chooses to run the program with an interpreter or compile it first.
The question is whether or not a work is derived from another work. It can be dynamically linked and still be derived, and it can statically linked and not derived at all.