Yes, and no!
Some of the pages you reference, operators, guards and unicode syntax, would fit in what I would call a language reference. The syntax reference, however, would not. It is mainly a description of the AST and only indirectly a language reference. While it is interesting if I want to write macros or write my own source transformations the AST is uninteresting to those who want to learn the syntax and it clutters up the text. So definitely keep it but not as part of a language reference.
Re the discussion of macros. For a language reference knowing whether something is a macro is actually not very interesting. At most all you would need is a tag saying whether it is a special form or a macro. What confuses the matter is alternate forms for do ... end (which unless you haven’t already guessed it I think is bad idea 
) but you could just describe both alternatives without going deeply into why.
