Most Helpful Guy
If someone gives a reason for being out of contact, assume that is why they are out of contact. It makes no sense that he was just being nice. No one would offer to meet up to write together just to be nice. Assume he was interested and for various reasons has been unable to be in touch. I know that it's hard not to doubt but it's just too soon. Hopefully you already heard from him. If some days after the end of the vacation you still have not heard from him, I think it's fine to contact him and ask how his vacation was.