You probably should wonder. I've seen different behavior for that with different Dahua cams/firmware. For at least one of mine, disabling the 'enable' box at the top does not stop the cam from attempting P2P connections. You have to untick P2P (and/or each of the other services below as desired) to stop the attempts to connect. On another cam unticking the enable box disables the services below. On another cam/firmware, it doesn't matter what you have ticked, it still tries to make a P2P connection or does other similar things (attempting to find Google's DNS) disregarding how you have things set.
I've not tested your case specifically leaving the enable box ticked with the service below unticked on whatever cam/firmware but if this is important, then I'd test it by watching the traffic using WireShark or other sniffer to see what it actually does.