Nothing will be reset, this is not a brand new coin so do not expect anything of such, the journey will begin where Ethereum left off, the problem is how this project will survive, if all what ETHW have to offer is just the PoW algo its going to die.
I think that PoW is enough boost for the ETHW coin for developers to start building their apps like they did in Ethereum and this will keep ETHW in track to become why not the new coin which differently from ETH may be supported by the miners and apps thus making it the new number one coin to be mined,of course this is the most optimistic scenario of all,if they did reset the Dag file which I find it highly unlikely,a lot of this coin can be mined in the beginning and this would also be beneficial to many miners,again this is another optimistic scenario.