cob

First of all, to clarify, snap bids only happen during recruitment and are offered before bid day so any girls who were snapped come to bid day with everyone else. So there will be no 'snap' bids, no.
COB = Continuous Open Bidding. Houses that did not make quota may COB, and houses that are not at total may COB even if they made quota but that doesn't mean they will.
Houses may want to initiate their current new members before they COB for a small class of new members, or may not COB at all. A house may hold informal COB events that could be open or by invitation only, or may just offer bids quietly to girls they already know.
With all that said, this was a weird recruitment and it remains to be seen what will happen.