When I was hired a couple of years ago, we were given aircraft assignments on the acceptance phone call and then had to wait 'til day one for the domicile. This came to a halt because of how fluid their needs were at the time. They were offering people classes in certain aircraft, then changing them to a different aircraft when they showed up a couple of weeks later. They recognized that this was not fair and began waiting until day 1 for assignments.
As far as a Feb 1 class, I can't say for sure that it's not true, but normally classes will start on a Monday. I think I remember a mid-week start date in late 2000, so I guess it could happen. You're the one who got the call, so who am I to argue?
True also is that more experienced candidates usually will go to the Brasilia because of what IFF stated, and also because it is a more difficult class and checkride. When I was hired into the jet, I was under the mistaken impression that it was because I had previous jet time. Truth be told, it's probably because I had LOW time and class is a piece of cake, relatively.
FYI, around the time I was hired, they were also hiring into the left seat of the Brasilia. Bad idea.