I thought my drip tray for my heat pump exchanger leaked (turned out it was the water heater and not the heat pump system.)

Anyway, I opened up the duct work and removed the drip tray for cleaning. It was full of deteriorated insulation and the exchanger above had remnants of insulation on the underside of the fins (the side that gets hit first by the air flow). I couldn't tell if it was blown there from another part of the system and trapped by the exchanger or if was an original layer of insulation on the underside of the fins of the exchanger.

Question: Did the heat pump air exchanger originally come with insulation on the underside of the exchanger unit/fins? (the side that gets hit first by the air flow) The exchanger sits over the furnace heat exchanger tubes and I think one side of furnace sheet metal casing below had insulation to protect from heat from the heater box and the foil on that insulation deteriorated. So I am not sure of the source of the insulation against the heat pump exchange unit. Was it originally there or did it get blown into the heat pump exchanger from elsewhere in the system? If it did then I assume I should clear away any insulation that is stuck/trapped on the heap pump exchanger unit.