That's just a unified memory architecture. Strix Halo has this, too. It's not only Apple. Memory bandwidth is lower than the ultra series but faster or on par for every other M series processor.
And it's great they are pushing each other. Strix Halo is based on Ryzen AI if I recall. My AI machine is currently Linux but I'd like to get a Mac Studio with an Ultra (or perhaps the M5 when it comes out) purely for the insane memory bandwidth.