Do we know what he divulged? How do we know this and how did the Washington Post, which is owned by Jeff Bezos BTW, get this info if the meeting was supposed to be confidential?
To be fair, the American media and members of the government can't keep their mouths shut, so claims from either side that any one has divulged sensitive info is a great case of the pot calling the kettle 'black'. Hillary made comments during a debate that should have gone unmade- what happened there? Robert Novack should have kept quiet when he learned that Valerie Plame was a CIA operative, yet he just couldn't.
No president is all-powerful and their staff should be able to reign them in when they go on a tangent. Whether Trump's staff doesn't try or they don't want to, it seems to be the first time it has happened. OTOH, I read a headline that said something like "Are we seeing the beginning of a coup?".