Next time, try researching before you write such a silly article.
ARM does NOT manufacturer chips. They sell/license IP for their architecture. Companies such as Marvell, Samsung, NVidia, TI, Qualcomm, etc manufacturer.
AMD could not possibly afford to purchase ARM. Even if they could, then what? I don't believe that ARM is allowed to compete against the companies who they license their IP to. AMD would just have a larger IP base, and some more income to sink into their declining x86 business. Maybe they could bankrupt ARM while they're at it.....