I have been using the materials from 8 years ago and they are working for me along with what I have been learning from the wonderful people here on the forums.
I think you should take advantage of the free registration and start now. I would think that any changes that happen within the next couple of months would be transitioned into the program as you attend meetings. I would find it hard to believe that WW would change and not allow members to take advantage of new updated information!
Go ahead and start.. you won't regret it!

OH, and welcome to this awesome place!