It's a distraction from the fact that they own you.
No they don't.
They don't own the work you choose to publish through their platform in any way whatsoever. By publishing it there you give them permission to use it[1], but no ownership of it. They have absolutely no claim on you, your future work, your past work, or any benefit you might receive from publishing with them. You can delete a story after you've published it, and you can publish it unlisted so it won't appear in any listings or publications on their site.
If you believe that's the same as owning you then you have a very strange definition of "owning you".
I suspect he was thinking of the older version [1] - I know that's the only one I'd even seen until you posted this link. The wording of the original is much more draconian, though [to my non-lawyer mind] it appears to say the same thing now, just much more politely.
No they don't.
They don't own the work you choose to publish through their platform in any way whatsoever. By publishing it there you give them permission to use it[1], but no ownership of it. They have absolutely no claim on you, your future work, your past work, or any benefit you might receive from publishing with them. You can delete a story after you've published it, and you can publish it unlisted so it won't appear in any listings or publications on their site.
If you believe that's the same as owning you then you have a very strange definition of "owning you".
[1] https://medium.com/policy/medium-terms-of-service-9db0094a1e...