I've always thought that these Year One wheels were more of a modern take on a 15x7" snowflake, than a 15x8" because they are flatter looking like the 15x7s tend to be. Which, since my car is a 77 came with 15x7s, fits my car to a Tee.
All in all though... I think it's more a matter of how modern custom wheels are made in general... look at almost all of them and they tend to be on the "flatter" side. If you look at those 15x8s above you can see that they were machined out of a single piece of aluminum, whereas the new ones have the snowflake pattern CNC'd out of a single piece, but are then welded to a "blank" wheel rim. If they machined them out of one piece they'd be so hugely expensive that they'd probably be economically unviable.