I think the githyanki fight is a good example of whats to come in term of damage. Height was an important tactical advantage against higher level foes. I doubt every maps will have this many height difference though. A small slope shouldnt have this much of an effect on the chance to hit, very frustrating. But when you are on a roof? I can live with that. I think they should increase the height requirement for advantage rather than removing it completely.
Low height no advantage, high height slight advantage.