Chalmers’ Zombie argument is the most surgically precise rejection of physicalism. Other thought experiments leading up to this one, aren’t necessarily exhausted by it. And it is in fact, wrong to assume that the target has remained exactly constant.
If there is something it is like to be a bat, we can’t infer physicalism is false outright. There are ontological, epistemic, and semantic aspects of the problem of qualia which have to be taken into account. Nagel had a problem it seems with science explaining everything, but held to a layered view of the physical world and his aim seems to me to be epistemic. The layers, epistemically isolated, but not necessarily ontologically. Nagel believed there could be “bridge laws” which translate the layers into each other.
So it would seem that the verdict on whether we can know what it’s like to be a bat isn’t exhausted in this thought exercise.