There's a huge difference. An URL is an absolute black box, a binary that you have to give Apple for certification on each change and that has to call Apple APIs to do anything useful (like network) is not.
Apple will scan your App to check for basic violations, that's all automated. For instance is there a specific flag that you can initialize a socket with to listen in background. This is only allowed if your app is supposed to stream music in background or do some VoIP thing. So if you're app is not that and the software detects you have that flag set anywhere in the code no way you will get it through the certification. There's simply no possibility for such analysis with a URL.
Apple will scan your App to check for basic violations, that's all automated. For instance is there a specific flag that you can initialize a socket with to listen in background. This is only allowed if your app is supposed to stream music in background or do some VoIP thing. So if you're app is not that and the software detects you have that flag set anywhere in the code no way you will get it through the certification. There's simply no possibility for such analysis with a URL.