How about this situation?
UA coded flight, US metal, US elite using US account
Do I get upgraded as a US-elite even though I am on the UA coded flight number?
It looks like this situation has improved for US Preferred fliers. This week I'm booked on a flight with a UA ticket with a UA flight number, but its a codeshare on US metal. With my US GP status I was automatically upgraded to FC at the three day window.