Well yeah, otherwise they would have to sell the tires as off road only, which would be ridiculous for a tire with 140tw. Wouldn't even be worth importing those, no one would ever buy them.
Here's a picture of the stamp on a RSRR if you actually need to see it, the newer RSRR looks like it got a 200tw stamp too, probably to allow it to be used in street class autocross, TT and chump/lemons.