I've never thought about the Ship of Theseus in those terms.
I always thought it was more of a "Are you still you even though all the cells in your body eventually get replaced; so except for many of your brain and nerve cells, you have little to none of what you were born with." or "Is it still that computer I build in 2005 even though I've literally replaced everything in it and the case, except for this old DVD drive?"
I don't think Ship of Theseus really applies here. The thought experiment asks, 'is it the same ship?' - not, 'is it a ship at all?'. It is considering identity, not classification.
If I kill you and then use your DNA to clone you ten years later, have I somehow not killed you? No, for the reasons GP puts forward (OK, philosophers might disagree, but I will leave that to them). But I have undeniably created a human, just not (necessarily) the same human I killed before.
We have a stable definition of "species", and if we create a genetically correct woollen mammoth, it is a mammoth, by definition, even if it's natural habitat is gone. Just like an elephant in a zoo is still uncontroversially an elephant, even if it has no capacity to survive in the wild.
From Wikipedia: In the episode "Heroes and Villains", Trigger wins an award for having owned the same broom for 20 years. He reveals that it has had 17 new heads and 14 new handles, but insists it is still the same broom.
I always thought it was more of a "Are you still you even though all the cells in your body eventually get replaced; so except for many of your brain and nerve cells, you have little to none of what you were born with." or "Is it still that computer I build in 2005 even though I've literally replaced everything in it and the case, except for this old DVD drive?"