I don't think so, either. Although it is sometimes much harder to prove a negative than a positive. But I have had another look at the tops of several Fora. In this context, there is an option to flag a Forum as Watched, or if you turn that off, the Forum by default becomes Un-watched or not watched.
What I have done for years is to click on the FORUMS tab in the main tool bar (f it isn't already highlighted) and roll the mouse wheel down about half a revolution. A down-arrow button (actually an inverted triangle) should appear on the right side of the FORUMS tab. Click on that down-arrow and near the bottom of the window that appears is Watched Forums. Click on that and you get a list of all new threads and new posts in existing threads in all of your Watched Fora. Unfortunately, any new posts in un-watched Fora that you might be interested in or that the sender put into the wrong Forum will not appear. An IGNORE button would be much better but I do not think that it exists.