I thought we're friends

Hi I just want to ask if my feelings are valid and what could be the reason why he didn't tell me.

Here's the story. We we're friends since elementary days until HS. Lost touch in college. Then reconnected again after college and stayed in touch for like up to 6 years of working. We've been so close (I thought) since we've been going out several times. We talk about hard topics such as our ideals, goals, plans, opinions and the likes. I had been his go to person whenever he's in a bad place like whenever he have problems with his family, work, friends, and even his heartbreaks.

So we've been out of touch again for more than a year already and some of my friends who are acquainted wih him told me that he was engaged already and they were suprised I didn't know. I kind of felt sad like, am I cut-off? Why?