I sent my Excel query form on the 1st February, about 45 mins after I received the email from Brussels Airlines.
After hearing rumours that the email was bouncing back for some people, I resent mine on the 4th and low and behold it bounced back.
So the scheme must have closed between the 1st and the 4th February. I am still awaiting my yes or no email by the way. Hope that clarifies some issues.