And here's a cap of Discourse's new topic creation, with category selection ability. Basically, I feel like constraining new topic creation only to within a single category topic list may not be the best idea.
I could be in the "Feature request" category list and easily think of an idea for a "General discussion" topic to create, and UX deems that those extra clicks to navigate to that category may stand in the way of low-attention span computer users.
Plus a new user won't memorize all the topic list types, so may be confused about why new topic buttons are only on certain screens.
I rest my case