> I think maybe is a clearer name for what the statement is doing and the lack of the 'do' block

It's because basically everything in Elixir is a macro :), and the do block is an argument/parameter to that macro:

   maybe x do
      ...
   end

   # is really 

   maybe x, do: ...

   # which ends up being a macro call with a named parameter

   maybe(x, do: ...)

Same goes for many (all?) other things in Elixir:

   if x do
      ...
   end

   # is really 

   if x, do: ...

   # which ends up being a macro call with a named parameter

   if(x, do: ...)

And so on.

But it took me a very long to come to grips with this, too :)