It seems valid.
I believe that the operator was made before the Reroute Node.

Another solution would be to automatically select the output socket when selecting a Reroute node.
Or take the first socket as a fallback if no "best_socket" was found on any node.
Or something more engaging like making a new type of socket indicating that it is a dynamic socket that takes the characteristics of the socket to which it is connected.

But I don't see any real advantage in these other solutions, so for me the patch is good.