Kushner doesn’t make much sense because he is part of this story as well.
Why would he want it to get publicity?
I’d bet Manafort before Jared.
One of the investigative commities might have been offering him immunity to come up with some evidence of “collusion.
This is weak collusion but the deep state would be happy to get its hands on anything.
I believe Trump’s team intentionally leaked this because they are trying to lead Mueller’s team to investigate the connection between this staged meeting and a FISA warrant request. I believe Trump’s team has already exhaustively collected evidence for months on Goldstone and the Russian Attorney.
By leaking details such as actual email threads and showing pictures of this attorney with Obama’s ambassador just days later, they are forcing the cards onto the table now.
Why would he want it to get publicity?
Let's not forget that Kushner recently filed an amended security clearance disclosure form that for the first time identified and included the meeting in question. IMHO the form was leaked first by an enemy of Trump, then the email was leaked to show the meeting was a nothing burger by a friend of Trump (maybe Kushner)...