bitcode predates that transition (which is very much still in play). watchOS and tvOS never had (consumer?) x86 versions, the bitcode thing was a workaround to

bitcode predates that transition (which is very much still in play). watchOS and tvOS never had (consumer?) x86 versions, the bitcode thing was a workaround to having to build fat (multi-arch) binaries for more space-constrained devices like the Apple Watch and Apple TV.