Project: DAWN is currently unknown about what exactly it is. All that has been released is a trailer for it, with some secrets hidden in the description. It can be assumed from these secrets that it is an ARG. There is also hints of a possible game for Project: DAWN.
It can be noted that the Project: DAWN videos are a lot different from most videos uploaded by LOD Studios.
The "REBOOT" trailer doesn't mean a new part of Project: DAWN, it is just a second trailer.