Talking about marriage and future good or bad sign?

My boyfriend had told me he is a relationship type of dude. His last two gfs, his HS/ early college they dated for four years and talked about marriage. He even asked her dad if it would be okay if he eventually in the future proposed.

Same thing with his last ex who he was inloveee with. He was prepared to be engaged to her I assume once they both graduated college.

So he’s very serious and into marriage. We have been fwb/talking since June and we started dating October. He’s brought up a few times about me moving in eventually in the summer. What kind of place I’d want to live and if we would get dogs, kid talk, asked if I would eventually marry him, etc.

He’s not jumping the gun wanting to get married ASAP. He doesn’t even want kids until early thirties. And I assume he’s not even thinking about proposing at all. And if he is it’s years and years in the future cuz I’m still only in my first year of college and he’s in his last. (I took a gap)

I just wonder if others bfs do the same. Is this a red flag or a good sign? I don’t get freaked about it cuz Ik he just loves thinking about the future.

Idk just wondering

* he never proposed to anyone. He just wanted to in the future but then they broke up*