Well, i've just looked at the whole sequence and that is the only shot where you may even see a reflection from the sabers. But upon a closer inspection the most you may even see would be the tip of Vader's blade. Here's a very quick sketch of the reflection
As you can see, Lukes stance is leaning forward and tracing the line of the leg that we can see , the line of the floor light and his other foot which is off the side of the floor light there is no way you would see Luke's blade at all. So, is it worth adding just the tip, even though you may not even see it anyway? I don't think it's worth it