The cold helps the lecithin disperse the particulate matter better Rad, but I don't know the particular science behind it. BadKat used to recommend a series of freeze/thaw cycles to get things broken down into finer and finer particulates, but Cajun told me outright that the freeze isn't necessary, just the cold of a 24-hour rest in the fridge.
I have great faith in his knowing what he was talking about. It doesn't sit well with me that I don't have a better explaination. KR might understand this part of the process better. I'll ask him, do a little research, and get back to you.