It is official that OG's 2 time TI winning roster will not be competing at the second major, Dreamhack Season 13.
Though nothing has been confirmed outside of this video in terms of whether N0tail will be coaching a different team that will compete, but it is heavily hinted at the end of the video.
It also shows Sockshka playing CS:GO. It has been confirmed that OG will be expanding the organization into CS:GO. There has been some speculation that Sockshka will be leaving his role as coaching Dota 2 into CS:GO by this video, but nothing has been officially confirmed on that front.