That, I don't know. They don't do it on MMs. But during the summer, some days they did it and others they didn't. I'm thinking maybe on the days they expect it to be busy they have the rope drop. Maybe someone else can shed more light on this.
We discovered that we didn't need to be in the very very front at rope drop to get a short line at Peter Pan or Star Tours FP machine (2 popular arrival destinations) if we "walked with purpose". So I wouldn't stress. Even in the middle of the rope drop crowd, you are still way ahead of most other people who will be at the park that day. Just know where you want to go before you get there.