I am UA 1K and have flown Swiss three times ZRH-ORD in the last three years, most recently last week. Each time I was on a UA (016) ticket, and each time I was upgraded at the gate to first from business on a Z fare. I never requested an upgrade and, of course, I have no status on Swiss (other than being Star Alliance Gold). Each time there were empty business class seats so they didn't need to bump someone up due to overbooking. I never received a text message, nor was I paged at the gate. The same thing happened each time: when I scanned my boarding pass during boarding, the agent simply handed me a new boarding pass without comment, each time with a first class seat assignment. Is it common for UA GS or 1K to be recognized this way on Swiss, or was I just really lucky three times in a row?