Well, you can do graphics programming in c++ or using a game engine and compile it to Webassembly.. So this language could definitely have a graphics library.
That's only because the host javascript which loads the WASM is exposing functions to do webgl stuff. When you use emscripten to compile C++ is to WASM, part of that equation is the JS runtimes that allow you to call translate openGL calls to Webgl, play sounds etc. It's possible to do with moonbit, but it would require some work on your part.