Penguin wrote about it a few weeks ago here: https://medium.com/lucid-nightmare/i-finally-got-my-first-warning-after-four-years-of-writing-ba3ae33eadc7

Your experience of getting warned sounds very frustrating, and similar to other accounts I've heard from people who've gotten warned - and is another thing that I think Medium does really poorly with respect to their rule enforcement. if you just warn someone without saying which post, or how to fix it, that is not constructive criticism. Medium really needs to get better about that.