There are several reasons to quarantine a new kitten/cat when first bringing it home. The two week quarantine period is set because this is typically the time it might take for illness to set in if the stress of the move triggers an infection. Since all of Cary's felines come from the same cattery it is highly unlikely that Regie will introduce a new bug that the other two haven't been exposed to yet.
The second reason to quarantine is to develop that bond between man and kitten - that will be up to Cary to judge but from what he has said, the bond has already been created.
The third reason is to allow the kitten to get used to it's new environment, starting with a small room and gradually expanding its territory as it grows accustomed to its new digs. Since Regie has already visited Cary's home several times he is already familiar the layout there, although he has spent most of his time in one room.
The final reason for quarantine is to allow the current four-legged residents get used to having a new sibling move in. This is the most fluid reason for quarantine, meaning that the other pets might accept a new family member right away, or it could take months to fully integrate the family into a cohesive, integrated group. It sounds like Kiki and Regie have already adjusted to each other. Azidi may be a different story but that will be another challenge for Cary to work through.
All in all, even though Cary hasn't stuck to the 'letter of the law' he has followed the spirit of the purpose behind the quarantine and I am sure that all will work out in the end. Cary has good intuition when it comes to knowing what's best for his cats, and I trust his judgment in this situation.
