This is long overdue. It was kinda crazy how you couldn't even visit a plain HTML page over plain HTTP without Chrome showing a "Not Secure" badge in the URL bar, yet downloading an executable file over an insecure connection produced absolutely no warning at all. You couldn't even manually check whether the file was downloaded over a secure connection without explicitly going to the downloads page. (I think Firefox is even worse in this respect right now, in that the only way to check where a file was downloaded from is to open the downloads library, right click an item, click "Copy Download Link", then paste it into a place where you can read the text.)
One thing I do find particularly interesting about this post though is the part where they imply they might start blocking all insecure file downloads at some unspecified point in the future. That would be a pretty major move.