I submitted my certified list on the first day it was available - January 15th or something. You can always change it if you want - even after certifying it. That way, if you should get hit by a bus or something and you are not able to enter your list, you still match!
Pretty much think that anything you hear at this point is generic and not specific to any individuals (their lists have to be done and turned in before the applicants' deadline). You should just certify your list today--there's no reason not to, and you can always change it after certifying.