I'm not so sure there will be a streamer weekend for the 3.0 update. It's basically lots of new settings to play the game the way you want to, but that's nothing very exciting to see in a stream, but much better to experience ourselves.
And if they have anything else in 3.0 that's new, then they would spoil it for everyone by showing it in a dev stream, or have people show all of it during the streamer weekend.
I think it would be best to release the 3.0 Experimental build when ready and let players discover things on their own. Maybe with Behaviour Interactive on board, this might be the case.