Personally, I prefer the green logo, it was very minimalistic and gave Medium an individuality. But it is a matter of taste.
The more important point, on which Medium team should work, is the design language of the whole site now. The green logo suited very well with the design of the site. The site and the logo had white background and a lot of green elements. Now this similarity is gone. The logo doesn’t represent the website. So I think that Your Friends @ Medium team probably should make some changes to the design language (for example change green elements to gray), so the logo and the website itself would have more similarities between them. Because now the logo is “medieval modernity” as you have described, and the website is still “2091”.
