Also, all progress during phase 3 will be wiped. Anything you get during phase 4 will be kept going into the release, unless something really big happens. There's always a very small chance they may have to erase progress again if something game breaking comes up. I don't expect this to happen though.
Unless an economy shattering exploit or something happens I doubt they will wipe out Phase 4. I'm glad they are keeping their options open but I don't expect to see anything major happening, the developing team seems to be on the ball and the community seems pretty solid.