The upper u-bend pipe (marked as 1) is there in the original design of the engine. It is also known as coolant bypass pipe, its main function is to provide alternate path for coolant flow from engine block to pump inlet line (metallic pipe) when the thermostatic valve is fully closed.
As @capsat mentioned above, all rubber hoses must be kink free to ensure free flow of coolant.
Lower pipe (marked as 2) connects engine block (from under the distributor) to heater core. As your heater core is not connected so the mechanic has directly connected this pipe with the thermostatic valve housing.
Normally this pipe is long enough and do not develope a kink when connected in this fashion, therefore I doubt that either this is a non-standard pipe or the mechanic has cut short it.
It is advised to change this pipe and also connect back the heater core, heater core doesn't affect AC performance if the blend door inside the heater box is properly working.
