Last year UW did things really strangely...when I interviewed there (during the second week of interviews), I was the only one there who had finished my secondary and the rest of my app. with them. Most other people got the interview invite before their secondary was complete. I don't know why it is this way, but I just know it was a real jumble, throughout most of the application process with them....but then, it was that way with everyone last year. And yes, MCW doea send the secondary to everyone. Get it in as soon as possible, as interviewing early there really helps.
Good Luck!!
Shannon