Match making based on being friendly or not? Any evidence of this?

I saw some people have been saying this and didn't think anything of it. Recently, some guy was sneaking about. I said I'm friendly he didn't reply so I played it safe and killed him and every game since it's been straight pvp which is alright buts it's a bit of a pain when out 20ish games I've only run into one friendly person (not including extracts). Idk if I'm just getting unlucky or whether this is a thing. But if anyone have any similar experiences or actual evidence I would love to hear it.