This isn't scroll jacking, any more than it's "scroll jacking" when there's a header or menu sidebar which doesn't move with the text. Scroll jacking means something specific, like the style which was introduced by NYT and has been imitated badly ever since, where sometimes scrolling triggers animations and then the text gets the scroll back.

Here, the main text moves up and down when you scroll, and there's an illustration on the side which changes accordingly. I'm seeing mixed opinions about that stylistic choice here, I don't have a strong one myself.

Just that it isn't scroll jacking. It's some other thing.