The idea that "all code is technical debt" because all requirements could hypothetically change someday, makes as much sense as saying "all currencies have no value" because 1,000 years from now we might not be using any of them.
Technical debt is not defined in terms of possible future requirements, it is defined in terms of current requirements. Code that elegantly and concisely expresses current requirements is debt-free. Code that is a mix of elegantly expressing old requirements, with new requirements expressed in a hacky fast way, has debt.
But trying to judge code in reference to all possible future requirements is utterly nonsensical. You can't measure that. It's literally meaningless.
So no, all code is not technical debt. Technical debt is technical debt, and clean code is clean code. Trying to redefine words to mean their opposite helps no one. That way lies madness.