They pulled out the ramp for the women’s race due to wet conditions. He probably WAS expecting a ramp!
He absolutely was expecting a ramp. You can tell by the way he just rides off the rock without pulling up on his handlebars as you would for a jump. Whether it was simply a brain fart in the moment or he paid no attention when told by his coach and teammates that the ramp was to be removed, who knows. But, yeah, the way he rode that makes clear he absolutely expected a ramp to be there on the far side of that rock.