I don't think it does, it just still hasn't been given a true boss battle in the canon. Think about it, in MGS2, you see the finished, manned-Ray at the beginning of the game, and throughout Big Shell, but when you reach the inside of Arsenal Gear, you see a shit-ton of mass-produced Rays implied to be inferior to the original one Solidus and Ocelot piloted. Then, you fight a bunch of them and it's easier than it ever should have been. When Ray makes a return in MGS4, you get to see the original one but this time, you have Rex on your side, so it's not an accurate man vs. machine battle that people became acclimated to during their time with this series. In other words, it's still not as hard as we wanted it to be. And lastly, you fight ANOTHER alternative Ray design for the introduction mission in MGR... it is by far the most exhilarating, but it's still easy as shit. It's the intro mission for Christ's sake.
