You think you're helping, but it actually really hurts.
One of the most harmful things you can tell an LGBT person when they're coming out is, "You don't have to change just because you've come out".
This is said so many times, in so many ways, but they all tend to veer towards an idea that "just because you're coming out doesn't mean that you should change who you are...."
That "change" is almost-always referring to "becoming more gay".
Before we come out, the lie we're telling is not just "we're straight" — we tell a million other little lies every day to feed that "One Big Lie". We lie with our body language. We lie with our affectations. We lie through our hobbies, our interests, our manner — everything we do is done to serve the One Big Lie. We avoid things that could be indicators of our secret.
We spend our entire pre-out lives being someone we're not, so when people say "just be yourself" it's an impossible task; we've never been ourselves. We haven't had the freedom to explore that, yet.
So please, don't place caveats on the identity and exploration of people who are finally on a path towards discovering comfort in authenticity.
You WANT the gay people in your life to "change" after they've come out — it's the mark that they're no longer monitoring and editing and compartmentalizing themselves out of fear of what they might be Presenting to the world.
And telling a gay person "You don't need to become a stereotype" only reinforces internalized homophobia in them, and strict (and SEXIST) ideas of gender-performance.