No, the Xcode workflow is set up to make applications CPU-agnostic by default, but there's nothing about the Mac App Store that requires it. The executables ar

No, the Xcode workflow is set up to make applications CPU-agnostic by default, but there's nothing about the Mac App Store that requires it. The executables are ordinary x64 binaries. It'd be perfectly valid to write an application for the MAS in x64 assembly, if you want, as long as it's sandboxed and doesn't touch any private APIs.