As you are already aware, threads that are debates are not appropriate on Subeta and go against the Community Guidelines. If you have to tell people to not debate, then you know the thread is not appropriate for the site.

If you have specific feedback to give staff regarding the site or any of the changes that were made, you can post it in the Site Feedback forum as long as you follow the Community Guidelines in your post. If you have concerns specifically about why the debate forum was removed, made a post about the removal and reasons why here: Debate Forums