According to the post on the dashboard, V3 is scheduled for sometime this month. In terms of content the only changes are: the rest of Season 7 lessons will be added, more practice pages at the end of lessons and the vocab will be changed around. New anki decks will be made to use with Anki 2.0.
In terms of look there will be more chapters per season but they will be shorter. You shouldn’t really need to go back and redo what you’ve already done.
I think you should just keep going through TF and when V3 kicks in all well and good. It won’t disrupt too much what you’ve done already. Also, as Zelda said, we don’t the exact date when the update will roll out. It could get delayed.