Summarizing, the page Viquipèdia Discussió:Apostes/Article 100.000 has the template {{discussió arxivada}} (talk archive) and it should not be flowified. Most talk subpages are historical or archives, so the current approach is to consider safer not to convert any subpage even if it exists its project page. Currently we are reviewing the criteria for subpages, either they could be redirected to the root talk page, or marked as archive, or moved to a new root page. Once reviewed, all existing talk subpages should be redirects or archives. The blocker is to do not convert any subpage or alternatively to do not convert any page with the archive template.
Some questions. Once enabled the flag $wgFlowOccupyNamespaces, if I create a new subpage and I want to redirect its talk page, I should ask to deflowify it, right? Is it possible to add any editnotice? Currently, if I try to edit/create or add a topic in a talk subpage there is a notice for considering to post it in its root talk page linked.
As for the other tasks, mark topics as resolved is a great new feature really helpful. It is a blocker for converting some key project pages like VP:PA. It is an improvement, but not really a blocker, for namespaces Viquipèdia_Discussió or Viquiprojecte_Discussió.