wasm modules can include their own initializers now, so .mem files won't be needed. This is the Data Section in the WebAssembly docs. .wast is actually just a

wasm modules can include their own initializers now, so .mem files won't be needed. This is the Data Section in the WebAssembly docs. .wast is actually just a testing file format that's currently serving the purpose of a text format in the absence of a real one. It isn't expected to be part of typical user workflows.