Yep, I also started participating in 2005 and I had to write a fic to participate. It was more or less like getting yourself cleared from a late default is now: you could pick any prompt from the previous year and write it for the NYR collection in order to be allowed to participate. (Once you were in, though, you were in - it was only a rule for first-time participants.)

I don't remember what year they stopped requiring this, and I really don't know why they even had this requirement. I suspect it was so that people would understand rare fandoms mean rare fandoms, here's an example, if there's nothing here you can write you won't be able to find things to write and request for the actual event.