Seems that this may only be true if you are traveling in the same cabin. I guess they don't want the companion in the front without the SE there to tell them that they shouldn't be drinking the sparkling wine and that the cheese tray or cookies would be served now if AC weren't cutting back.

I just talked to someone and got further confirmation. The issue is that they are currently on different booking references and therefore are not considered traveling companions by reservations. However, had they been on the same booking reference, as there was only one seat neither of us would have been upgraded. So basically no way to do it. They did confirm that at the airport I could do, but at that point it would be stupid as they would be further back in the list than me.