I heard someone who thought he was Gregory

Henry doesn't have a son

Yes he does

In the novels, but not in the games.
And his name is Sammy not Henry

Oops got stuff mixed up

He still has him as a son tho

The books and games are two different timelines

I assume you mean Sammy Emily, Henry's son from the novels. He doesn't exist in the games, but in the novels he left with Henry's wife when she divorced him. So either way he never really shows up. Hope this helps!

I have a theory on what happened to him

Oh boy

So Sammy, in the books, not games, is practically just a normal human now- he witnessed his sister get kidnapped but eventually forgot and lived a normal life

What about in the games

he doesn't exist in the games, or isn't important at all