Have traveled J 2 return routes in past 2 months on Silver and never been OP-upped to F even tho the plane was empty

I called up the EK office and spoke to them about Gold benefits as i am going to achieve it in 15 days and why I should stick to EK over 9W as 9w offers upgrade vouchers to Plat members and the office desk told me I can ask for a complimentary upgrade at the check-in if there are seats available... wonder if its true or if she was just telling me this to get me off the phone.