I've never seen my posts being re-organized on their own. I know, however, that Team Hashnode takes care of their platform and, in the past, they edited some of my posts with the "edit" feature, so that I could approve their changes.
I do not think that there is an AI which just changes posts, and node admins and moderators do not have the right to do so. As a conclusion, it's probably still someone from Team Hashnode who edits your posts.