On the topic of COBTs: quite often airline reps are consulted when arrival rates (hence COBTs) need to be changed. It is not uncommon for the consensus amongst airlines to carry extra fuel and take the holding, as opposed to copping ground delay on their COBT. That way the airlines maintain OTP with respect to departure, and can blame ATC enroute when they are given holding.
Personally I would suggest (if time permits), ring your company and ask questions.