We (meaning the whole industry, WDI included) have been talking amongst ourselves for the past 7 or 8 months getting excited over how good this project really is. The past week has been all of us industry-ites basically fan-boi'ing like you wouldn't believe.
Those who have been inside and have toured are in love with the detail, and those who haven't are drooling to get in just as much as everyone else, if not more.
If you like detail, this will blow your mind. And that's before you get into Gringott's or get on the train. It's really that good. It's DisneySea/the first time you rode Indy good.
So, yes, the people at WDI look at Diagon and go "that's totally awesome!!!".