I don't think Leno is the market draw for the age group Foose and others would be. He has an awesome collection, yes, but my kids don't even know who he is.
As far as collaborating, I think the Gearz deal is a win/win. The contest and presence on the show help Revell sell kits, which means thu can make money and all that follows. We builders get a newly tooled kit based on Stacey David's car.
The main reason to put recognizable names on a model box is to draw new customers. Somebody unfamiliar with the hobby could care less if Revell has a new tool '57 Ford. They would think it's cool to see a Foose model, though, something "regular" customers may or may not give a hoot about.
So, what was the question? Oh, I think they need a balance of dropping names and developing new kits - much like they are doing now. Seems like a good balance as is but I don't know the numbers on sales, so...