While it's best for these changes to all be in one place now, in future it'll be confusing. In 2017 no one will care that the changes were introduced in 7.
Maybe the manual needs a stronger 'this is what we say Prolog is' focus and less 'here's where we are in the prolog world' focus? Writing the manual as if we assume you've never heard of prolog might be clearer for experienced users as well as beginners.
The manual really never says 'this is our syntax'. Instead it says 'we're ISO except for these 23 things'. That's not really helpful for the beginner or even the experienced programmer looking for 'I want to use . as an operator. What's .'s status?' or 'how do I represent the formfeed char in an atom?'