First is who cares about large corporations? Sure large corporations have the money to buy licensed software, but I know plenty of small-to-medium corporations that operate on pirated software.
Second is your statement doesn't mean anything at all. Yes, you can enact a policy in your corporation that no one is allowed to use AI tools like Copilot to write code, but how do you monitor this? How do you know if some developer did use Copilot? This all feels like complete lip service with no actual force behind it. I am 100% sure that even my corporation's code base already contains stuff written with help of an AI, but there is also no question that the code is fully copyrighted.