My original thread has been badly sidetracked so many will have given up on it.
A few useful posts came early on, and it has been confirmed over in the Community thread that it isn't a typo on the web pages.
That thread as well has got rather long, but in essence the change is similar to all in the past. Those on the 38/20 will stay on it until they change of their own volition to another product.
What will happen with retention deals hasn't been resolved. I doubt if it can be, as only the Customer Options Team can decide, possibly on a case by case basis. I think past history shows they may be able to get one and stay on 38/20, (or the earlier 38/10 even if that's what they are on), or they may have to move to the then current product to get a retention deal. It seems to vary.