"Beyond the MVP" is the key phrase here. The first version of webassembly will not be able do that. Just like it won't have dynamic linking, SIMD, shared memor

"Beyond the MVP" is the key phrase here. The first version of webassembly will not be able do that. Just like it won't have dynamic linking, SIMD, shared memory (pthreads) or support for garbage collected languages. It's worth noting that those features were already on the path to being added to it asm.js before webassembly was even being worked on. Most of them are still going to make it to asm.js first.