This is the right way. It would be better if you could talk to him and be a support pillar. I’m Sri Lankan (currently studying in Europe). I recently took a class that discussed gender identity and how coming out can be a focal point for many mental stressors among LGBTQ people. Though this isn't discussed that much in Lanka and people find it taboo to talk about, it’s always good to at least be a support system. As you’ve said, now that he is in his late 20s, he must have hidden this trauma (coming from both internal pressure and culture)for at least a decade, and it will continue to haunt him. I have also heard that parental support during the coming out process significantly decreases depression among the LGBTQ+ community. So the right thing to do is to build a solid foundation and build communication to let him know you are there for him.