Just adding my experience here.
Flew DOH-DXB-IAD on UA 977 on Oct 21 in economy.
Was denied access to the Oryx Lounge in Doha as an Aeroplan Star Gold.
I asked for a lounge voucher at the Business Check In and was politely told that There was no Star Gold lounge in Doha and they would be unable to accommodate me.
Although- having been in the Oryx Lounge courtesy of Ethiad Business class, you won't be missing to much. The lounge is dry and the catering is so so.