I agree that a change may be necessary but not so sure about the specific change as proposed.
Having a personal history as noted in What type is a single quoted string? to me this is just the tip of an iceberg. A change should note the ISO Prolog standard and how SWI-Prolog can differ with the use of Prolog flags. A change should also show examples of using the type checking predicates such as atom/1, string/1, is_list/1, is_of_type/2, and output predicates such as write_canonical/1, etc. as a user would expect those to be in-sync with the description. This then leads to the idea that an entire bottom up review of all of the related definitions and usages be checked and re-aligned as needed and then this could become a mini-thesis project.
Examples of some predicates for demonstration but not an exhaustive list.
?- atom_codes('abc',String).
String = [97, 98, 99].
?- atom_codes('abc',String),string(String).
false.
?- atom_codes('abc',String),error:has_type(text,String).
String = [97, 98, 99].
?- atom_codes('abc',String),error:has_type(chars,String).
false.
?- atom_codes('abc',String),error:has_type(codes,String).
String = [97, 98, 99].
?- atom_codes('abc',String),error:has_type(string,String).
false.
?- atom('string').
true.
?- write_canonical('string').
string
true.
So while I agree the idea is noble, I also see it as a potential problem for others learning in the future, as an example from a different concept; while I understood use_module/1, having seen consult/1 in a directive confused me ( Using consult in a directive to load source code; it puzzles me?) because it was old but until I learned it was old thought it might be new and the better way to go. Only having asked and getting useful feedback did I learn it was not the way to go. So a user new to Prolog might find conflicting descriptions and then pick the wrong one, which I agree is part of your goal, but also has the potential to add conflicting knowledge. So I believe that any update should also show correct and incorrect ways to use the predicates with SWI-Prolog and also with ISO Prolog in case a user is using another Prolog but reading the description at SWI-Prolog and extrapolating that to the Prolog they are using.
As always feel free to disagree or ignore. 