You don't want to transport heat a far distance (thermal loss becomes too high), so keeping the vent for the refrigerator integrated into the unit is generally better than shipping it off outside.
CoP is the lift you get from a heat pump given a specific delta-T. The smaller the delta-T (like an air conditioning unit's 90F->70F), the more efficient you can make it. If you group a bunch of components together with different target temperatures, you'd either effectively have 2 lines (so 2 systems), or run the system at the lowest temperature you care about. 2 systems is what you have today, and 1 system with high delta-T would have a much worse CoP.
Also refrigerant has a very high carbon cost and installing piping on site between all of these appliances would require more refrigerant to fill those pipes and a higher potential for leaks.
Refridgerators are pretty low power. Transporting heat works fine for tens of km in district heating. But you probably have some better energy efficiency investments than building insulated pipes and a secondary water circuit + heat exchanger or running long stretches of expensive refrigerant in the pipes, for the fridge's 50 watts worth of heat.
You don't want to transport heat a far distance (thermal loss becomes too high), so keeping the vent for the refrigerator integrated into the unit is generally better than shipping it off outside.
CoP is the lift you get from a heat pump given a specific delta-T. The smaller the delta-T (like an air conditioning unit's 90F->70F), the more efficient you can make it. If you group a bunch of components together with different target temperatures, you'd either effectively have 2 lines (so 2 systems), or run the system at the lowest temperature you care about. 2 systems is what you have today, and 1 system with high delta-T would have a much worse CoP.
And other reasons...