I dont think blackrock stayed any longer than xside, or cs or smite etc. and they certainly didnt win any pvp with same numbers.. I think everyone is on the same page, admins took WAAY too long to add these new features, they didnt even reply to the 10 + threads asking about it. All clans would continue to play if there was a reason to, win or lose, and for that I kind of agree with you hush, blackrock / future and some of those clans do hang around longer than others, regardless of the standings.
Who knows, rumour is admins adding some stuff in next few days, and making static timers for a few epics to encourage some pvp in prime time. But it could be too little too late.