After 6 years on Medium I can 100% state that editing the content (unless radically changed) of the story doesn't affect views one bit. Changing tags and title however, definitely will have some effect. I regularly edit my articles post-publishing, because I find a typo or something, even after 2-3 rounds of editing. If anything, these edits should only do good for views, especially if the edits improve SEO. It's normal to have huge jumps and drops in views on Medium. This particular instance is a coincidence, nothing more.