I don’t think it was unreasonable to expect a yes or a no, but that doesn’t mean you were going to get one. Lots of times expectations aren’t met, which is the biggest problem with expecting things in the first place.
I think he was probably letting you down gently or possibly trying to keep you on the backburner. I don’t like that he told you not to rush something, because I don’t think you were, and saying it like that makes it sound like you were doing something wrong… and you weren’t. It was perfectly okay for you to write and say it was nice to see him and ask to meet up again. He could’ve simply let you know that he’ll let you know when he was free instead of adding that last part.
At any rate, if he was excited to see you again, he likely would have made a date with you instead of saying he’d let you know, but I don’t think this guy is a big loss.