the crypto and media codec stuff are not part of the CPU, they are IP cores on the same SoC as the CPU. So to update to the new media codec and crypto, you can

the crypto and media codec stuff are not part of the CPU, they are IP cores on the same SoC as the CPU. So to update to the new media codec and crypto, you can spin a new SoC with the same CPU as the previous one but with added IP cores. The CPU can be ARM or Mill, it won't matter, and the IP cores are exposed to the CPU as IO devices though MMIO. I don't see the big advantage for Mill for this application.