I tend to think that you should interpret the PragProWriMo in a way that you think will work best for you. Often, I find the “write now/edit later” mantra helpful in getting me out of situations in which the writing freezes up while I ponder some knotty situation. For this month, I’m trying to get a lot of text out on the computer for me to edit later. At the same time, I’m also doing some amount of copying and pasting of old writing that I did into my current book. In this situation, I’m finding it helpful to not rewrite stuff I probably also wrote in some other context; this process of editing is what is needed instead.
The key for me is to use this month to participate in a communal process of writing together and encouraging each other and to focus on making daily progress.