Might be too close to this question, but would questions relating to expanding or basing oneself on existing languages be on-topic on this site?

Take for example the recent explosion of C++ successors (Circle, Carbon, Cpp2), would a question like 'What C++ compilers are simple to modify syntax on?' or 'What are some syntax options for simpler generic functions' (like Cpp2's arg: _) be on-topic?