This has zero to do with the ports being "privileged" and everything to do with their state as a "well-known port range" used by "IANA-registered application(s)

This has zero to do with the ports being "privileged" and everything to do with their state as a "well-known port range" used by "IANA-registered application(s)". The idea being you can adjust the timeout because you can infer the way the port is being used.