Who knows, maybe Rossi finally started putting 1/2" tall front sights on like they should have in the first place.....
I got mine to shoot point of aim when they first arrived in Canada but I had to remove the elevator and file the slot you are talking about down a fair bit in order to use the factory front sight Rossi was using at the time.
What I like with buckhorn sights is they offer several easy aiming points that can be used for hold over on longer shots ,without moving the sliding elevator,