I doubt if it’s a standardized or university accepted term but still, going by logic, macro SEO is group-level SEO used to promote a bunch of websites for one or more keywords across different search engines. Micro SEO, in contrast is site-level SEO (optimization of one site) across different search engines.
These seems something new, I have never heard about such a term in My SEO Career. Thanks for the insight but still require more information.