From my understanding, ThinQ is LG's line of smart devices across all their products, so they weren't going to use something different for their phones. I'm also guessing it's a cultural thing that sounded cool to the advertising people in Korea, but it just doesn't sound cool in English.
As far as AI features going to the G6, I reached out to LG through the Quick help concierge, and the person who helped me said the carriers would decide what updates the phones would receive, and I guess that includes AI too.