I'm doing Slimming World and it has changed ever so slightly in the last eight years or so since I went along to a class. There are some new additons to the healthy extras, such as Ryvita mini's, plus you can have either 1 or 2 healthy extra (a's), plus the usual healthy extra (b's).
All in all though it's pretty much the same and the old plan certainly worked for me so if you have it already, I wouldn't think it was urgent to get the new details
I hope you get to where you want to be for your wedding, winter weddings are lovely!