Welcome to the site !!
About the only way you are going to know is to test fit the wheels .... I am thinking the front wheel will work , but the rear might be a issue , but I am not sure , as the width on the hub at the sprocket is different on the 17-21 R/RX , so the rear sprocket is offset around 3.75mm on the R from the older gen bikes , not sure if they carried that change in setup over to the L .... but that is where I think you would have a issue , the only other possible issue may be the axel diameter in the front ... especially being a 250 , the axel and fork lugs may be different/smaller .... so , honestly the only way to find out , is to test fit .... maybe if you have a friend that has a late model R or RX (17-21) maybe he would let you do a test fit , either by placing your wheels on his bike , or his wheels on yours ... As I am not aware of anyone who has tried this setup ...