You know, I was contemplating asking this very same question. I just got to that lesson of Christopher's too, and noticed that. But my chord charts have the R finger and not the pinky on the E. I've also been jumping around the lessons, and one of the finger-picking videos that Lisa does, she does a G with the R finger and not the picky too.

But, Razbo's, answer makes a lot of sense. And, even though you say "I only play the pinky-on-the-E form if it is required ", I take it that means you practice/learn it both ways so you can have an additional "tool" in your playing?

I also note with some interest that it's very similar to the answer that someone (razbo again?) gave when I asked how you know where on the fretboard to play the same note, out of the multitude of possibilities. And, the basic answer was "it depends where you're coming from and where you're going"....

So, once again, THIS newbie thanks you for sharing the more advanced perspective to integrate into my learning... Sometimes it's so easy at the beginning, while trying not to get lost "seeing the forest for the trees", to lose sight of thinking about where you want to come OUT of the forest on the other side :)