Posted by asotobu on Oct 27, 2013; 12:23pm
URL: https://discuss.asciidoctor.org/extension-preprocessor-tp886p887.html

Preprocessors are executed before starting to render the document, so include macro is not executed, it is executed during render time, for this reason the include content is there during preprocessor. In this case what you is a TreeProcessor or a PostProcessor I guess.