The problem with this take is the assertion that LLMs are going to take the place of secretaries in your analogy. The reality is that replacing junior devs with LLMs is like replacing secretaries with a network of typewriter monkeys who throw sheets of paper at a drunk MBA who decides what gets faxed.
Point of clarification: DAC is copper, AOC is fiber.
A lot of 10G equipment will support 5G/2.5G SFPs as well, so it can still be beneficial to go 10G on the core equipment.