I have the same impression wrt yuletide letters. I'm hoping that more will appear now sign ups are closed - but I've refreshed the app so many times over the past week for all the fandoms I'm interested in (not just the ones I offered for) and been baffled at how few letters there are. some of the fandoms I like have no letters at all. I don't know how I'm supposed to write treats if there aren't any letters? :/