The repack doesn’t check your current version. It overwrites and adds the missing side-by-side assemblies that modern Windows erroneously ignores. directx end user runtimes web installer repack
That tiny file is just a downloader. Every time you run it, it reaches out to Microsoft’s servers and downloads the specific DirectX libraries your system is missing (specifically the legacy DX9, DX10, and DX11 files that modern Windows 10/11 doesn't include by default). The repack doesn’t check your current version