I don't think there is a magic formula on Medium, but, in a general sense, I would disagree with this article. The more popular writers post everyday--and they aren't scared of writing about the same thing--more or less--everyday.
There was one popular writer who put up at least 10 articles about her affair with a married man. Same story, slightly different twist. Her followers seemed to like it: thousands of claps. I unfollowed her.
But there are a few writers I follow who do write/post everyday and don't seem to be going anywhere fast. So "daily" is not a guarantee of success.
For those who find a particular combination that works here, "daily" becomes the way to make more money. It that means regurgitating the same stuff that worked before, so be it.