Wasm is designed to deal with the VM sandbox, which if you're writing a server is fantastic compared to actual native code as there's better security properties.
It's not fantastic if you're working on an Electron app where there might be one specific feature that requires a native module in order to hit an OS API that you can't do from a browser sandbox (and that Electron itself doesn't expose).
Rather than pursue total deprecation/eventual removal of postinstall/native modules, I think a package.json "allowNativeDependencies": "never" | "devOnly" | "always" option that defaults to "devOnly" if not specified is the way to go.