I don’t think he told anything to Trump that would be secret or dangerous. He met with him as a hedge on the off chance it would help should Trump win. He has to.

The reason why I'm skeptical that it's just "letting him know the victory plan incase he wins the election" is because he's already personally aware that Trump is transactional. I know, I know - there's nothing else to see here. But it's a really bad look - especially given the past.