Based on the comment about uninstalling Flow from Commons (T186463) by @DannyH, Flow is a ticking bomb of technical debt on every wiki where it's installed. Flow allegedly puts the wikis into an irreversible state whereupon it becomes impossible for the Wikimedia Foundation to handle its leftovers.
If the mere presence of Flow can unwittingly produce an unintended and irreversible decision on a wiki, limiting the ability of the Wikimedia Foundation and the project themselves to consciously decide how to manage a wiki, it becomes imperative to uninstall Flow on all the wikis where this deadlock has not yet been created.
If I understand correctly, Danny's concern is raised merely with the existence of a page in the "Topic" namespace, not as much with any related log entries.