I know a lot of people who have had gold rings become misshapen after a few years of use.
I've heard people say this before but I don't know anyone who has had this problem. I thought it was more often a problem if wearing two different carat golds together (though prepared to be corrected!).
I've worn my mum's gold wedding ring for the last 10 years and she wore it every day for 50 years before that and it still holds the same shape.