There are a few builders that make necks this way.
Linc Luthier has done it for years.
AFAIK the Benavente "B-style" neck is made like this as well.
Finally - wasn't JP doing this for a bit?
The original, "real" Parker Fly basses were made with a 16-ply laminated mahogany neck, with the glue lines in plane with the fretboard. The whole glue layup was done in a big press, with shaped cauls, so the laminates actually bent in a shallow "S" shape along the heel and continued unbroken into the body mortise. Neat.
My gut reaction is that it's not really that bad an idea.
Actually, I could make a theoretical case why it would be better than vertical lams (perpendicular to fretboard plane), since you could put a high tensile-strength material on the rearmost surface of the neck where it can do the most work.
However, as always, the question should be "why?"...I'm all for trying new things, as long as they are motivated by some kind of clear goal. Are we recovering some otherwise too-thin lumber? Trying to change the neck's behavior? Reduce weight by using a softwood middle layer? A different neck-to-body interface?
If it's just to be different...well...OK, I guess...but wouldn't it be more fun to have a real reason?
Frankly, I think that vertical laminations developed as a result of people wanting to make quartersawn necks from flatsawn planks by ripping them up into strips and gluing them edge to edge - I'm thinking of many older archtop guitars I've seen.
It wasn't long before someone put some accent veneers in there, and it became an aesthetic. That's my guess.
Cheers,
Martin