I mean, it would be fine if they did add it as it wouldn't really harm anyone, but there is an indicator next to each person's name in the party list that shows just how much enmity they have on said monster compared to you. I'm not sure why anyone would need a gold star to verify that. Though I do think the idea of a gold star for enmity is cute and I would be cool with them changing the red symbol to a gold star. :P