Uplink Selection policy - Follow Global Preference ,
If you set an uplink selection policy of Follow global preference for example - tcp any to any : port xx yy. Then it would go back to the uplink selection of global preferences & go via whatever Primary uplink is set or load balance it if this option is enabled.
Now, for example i dont have an uplink selection policy of Follow global preference tcp any to any port xx yy it would still go via Primary uplink or load balance it.
Am i a fool keeping this policy for an year or does it really has some use ?
It has a use when you look at a larger, broader rule set. Consider that you have a subnet that you want to create an exception from the global policy for, but for some reason you have a single host in that subnet that you do want to follow the global policy. You'd create the rule for that single host to use the global policy, and then create the rule for the subnet to use the exception.