WebAssembly CG members representing four browsers, Chrome, Edge, Firefox, and WebKit, have reached consensus that the design of the initial (MVP) WebAssembly API and binary format is complete to the extent that no further design work is possible without implementation experience and significant usage. This marks the end of the Browser Preview and signals that browsers can begin shipping WebAssembly on-by-default. From this point forward, future features will be designed to ensure backwards compatibility.
See this message on the community group mailing list.
The WebAssembly community group and contributors plan to:
0x1(from this point forward all new features will be added in a backwards-compatible manner, and be detected through feature-testing). To update your WebAssembly modules, upgrade to the latest version of Emscripten and recompile.