So,in the winter you can go to the house in Icirrus City and he tells you about the time of Team Rocket,so if he USED to be a Team Rocket member,and In HG Team Rocket is in existance...then is he in HG as a Team Rocket member?
Yes he is,he's the Team Rocket Grunt who stole the Machine Part from Kanto's Power Plant in Gold, Silver, Crystal, HeartGold and SoulSilver (You can tell by his speech pattern). Here's the source