The disagreement was actually all over whether the question was about a switch or a button, and so some people were answering as though it was a switch, and some people were answering as though it was a button - switches and buttons do indeed have opposite approaches usually (a switch usually shows the current state - such as "on" - but a button shows what action will be triggered by pressing it, such as "play").

that post is about toggle buttons, not switches. e.g. a play pause button, when pressed, does it show play, or does it show pause?

There was a thread elsewhere asking whether a toggle should show current state or the state desired.

there it is

It really depends on the type of control and what it's controlling. As this is a switch, you'd expect the current state to be what's shown on the same side as the slider-- in this case, the slider is a sun in dark mode and a moon in light mode, which is the opposite way.

The designer team once did a toggle button with the inverse logic and I was so confused when I had to implement that. It must be my antithesis.