The devil's in the details, here.
Here's Medium's relevant terms of service: You own the rights to the content you create and post on Medium. By posting content to Medium, you give us a nonexclusive license to publish it on Medium Services, including anything reasonably related to publishing it (like storing, displaying, reformatting, and distributing it). In consideration for Medium granting you access to and use of the Services, you agree that Medium may enable advertising on the Services, including in connection with the display of your content or other information. We may also use your content to promote Medium, including its products and content. We will never sell your content to third parties without your explicit permission. https://medium.com/policy/medium-terms-of-service-9db0094a1e...
Contrast that with https://terms.hackernoon.com/ : We may use Your Content in a number of different ways, including by publicly displaying it, reformatting it, incorporating it into advertisements and other works, creating derivative works from it, promoting it, distributing it, and. As such, you confirm and warrant that you own or control all rights to Your Content and hereby irrevocably grant us world-wide, perpetual, non-exclusive, royalty-free, assignable, sub-licensable, transferable rights to use Your Content for any purpose. Please note that you also irrevocably grant the Users of the Site the right to access Your Content in connection with their use of the Site. Finally, you irrevocably waive, and cause to be waived, against Company and its Users any claims and assertions of moral right or attribution with respect to Your Content.
Typos aside, HNoon is asserting far more rights than just "we're getting the same terms that Medium got when you first posted there." Particularly, I believe (IANAL), the waiver of attribution claims against other users of HNoon means you are effectively releasing your work into the public domain, to be used without attribution by anyone who finds it through HNoon.
To the extent that HNoon was trying to "sneak this through" with their friendly message to authors, it's a scumbag move. It's good that they're updating their language, and hopefully they change enough.