Potter was a relatively untapped market for merchandise and Universal jumped on it and they’re still bringing out new ideas and I’m sure they have more in the pipeline. Star Wars is over 40 years old and everything that can be done has been done already and it’s available everywhere. Unless they bring out some great park exclusive merchandise, I don’t think they’ll be seeing a huge increase when Walmart have similar stuff for far less money.
I think the bars and restaurants will be a hit for the experience but I’m not expecting anything great from the food.
I also don’t think blue milk will be a success. Like green eggs and ham, it’s a gimmick and as a species, we’ll just find the idea repulsive. People will buy it for that instagram photo but it’s a one and done thing. Butterbeer in comparison is a decent drink and unique.