>>49602499Turboautists like yourself have a very hard time reading Goh. Anytime you see him have a normal interaction, you point at the screen and cry INCONSISTENCY when Goh's never been incapable of interacting with new people. He introduced himself to Ash, Delia, and many other characters just fine from day one.
Goh has defensive, guarded interactions when he feels as though someone is being disagreeable, making fun of him, or pigeonholing him into a role he doesn't agree with. Years of being a loner, and probably being somewhat bullied for his Pokemon obsession have led to this. His miscommunication with Tokio also led to a fear of being abandoned or disregarded.
If he isn't being bombarded with comparisons to Ash or being mocked, he functions fine and is often happy to meet new people, especially when its a means to learning more about Pokemon. As of meeting Gary, Goh is taking a proactive approach to his insecurities by trying to prove himself in Project Mew. His character progression might be hard to follow for you because they aren't pointing it out and verbally explaining everything.