DragonFlight Creation question

My question pertains to how it’ll work once they release Dragon Flight xpac at months end. Do I wait til then to make a toon for it and make it a dragonkin build or will they be taking a toon of my choice and making that toon into the dragonkin form ; sorta like what they did with the Worgen race?. I’m sure there will be a level requirement for it if they go with my 2nd possibility; if so, what will that be?..50?.. I just dont want to take all the time leveling a toon expecting that one will become the new dragonkin of my choice if we start off with one at lvl 1. Please let me know on this. Thanks.