as far as i know SE has never given advice on how to set up a party, or what role a class will take. the amount of times ppl have asked for clarity on is a PUG an evade tank or a DD? its a question still left unanswered. so i can't see them telling you how they see CON being used, its the sort of thing you need to play around with and find your own style. if it makes you feel any better tho, i believe everybody will have to play around with classes and party set up to figure out wha works best for the new battle/combo system, its new ground for every class not just mages
healers will always be in demand as will a tank as will a DD, its a holy trinity