It's been ok to admit to being a dissident for twenty years by that point; it's just that many people, after years of living in fear, still aren't very open about that. I think that neither Gul Zamarran not his brother would talk about that. But young Zamarran doesn't remember the times of fear that well, so for him there's no problem. He knows how terrible the Obsidian Order was, but he never experienced that horror.
I think Jarol knew how to talk to him, because I expect she had such a conversation with her son. Sh used different examples, but I'm sure she wanted Laran to know how bad it used to be and how important it was that such things wouldn't be repeated.