AH the question, year after year, nobody seems to know the answer too. Every year I go in every day to all the stores and ask "When will the lanyard be out?" "When will the merch be out?", every year we get as many answers as the people you ask, and every stinking year the merch comes out either later the same day or the next day after I asked and nobody at Uni knows.
For example I've already been told the lanyards came out last week and they sold out (har har), last Friday, Today (Monday) and opening day (this Friday). All by guest services employees.
I had a myriad of similar answers about the merch for this year from various employees. So I guess the only real answer is "When it comes out"
I honestly have know idea why they wait so long. The more you sell earlier... the more you make or the less you have at the end.