AMD's Navi 48 graphics processing unit, based on the RDNA 4 architecture that the company briefly demonstrated yesterday, is significantly smaller than its predecessors from the RDNA 3 generation.
It's possible that there are other motivations, though; all of the processors AMD announced at CES use RDNA 2, RDNA 3, or RDNA 3.5 graphics, and AMD may have wanted to avoid stealing their thunder ...