Thanks for reporting it, we were recently advised by a customer’s accessibility team that the topic list should not use the heading role and this lead to the removal…
Seems like the headings were preferable, and I think we can add them back if there’s a good case for them from actual people using screen readers.
Are headings in a list of topics like this expected behavior you’ve experienced on other sites too? or is this sort of thing unusual but nice to have?