Predicting it now. A large part of the "why" is going to be because of the jump in data science. Python is an incredibly kind language to new comers in the sense that it allows you to just get started. A lot of people are making bigger jumps into data science (purely anecdotal) in the sense that they are programming more around it. Scraping data, cleaning data, etc is also really easy with Python.
Devops stuff is also a great one to pair with Python.
Reason I'm predicting this: I've kept an eye on Python+Flask /Django jobs for over a year now, and while I see "Python" show up more frequently now, "Flask" and "Django" are still about as frequent as they were in the past.
Looking forward to the "why" post. Glad that they mentioned that they'll be publishing that soon.