But it’s never going to be 1:1 duplication is it? Sometimes it’s better to copy code as a template for something new, rather than try to immediately force a new abstraction.

I agree with you that it’s a truism, but it’s useful advice for people who have a habit of trying too hard to DRY their code. IIRC the author comes from the Ruby world, where DRY was a big thing, and this talk was part of the pendulum swinging back away from this DRY obsession that sometimes just resulted in convoluted code.