How the residences work afaik:
- if I get (catch/hatch/recieve via event...) a Pokemon and i trade it the residence list will only list the receiver's location. I have a PGL Tyrunt that I got myself from a code the location list is blank atm but if I trade it then the receiver's location will be added. I also got a WHF15 Rayquaza (that I know was legit) and the location list only has my location.