I don't know if this is a bug or a design decision…
When adding Start and End dates to a Forum and putting those dates on the calendar, nothing appears on either the Work-to-Do widget or the Pulse app. They do appear on the course calendar.
Adding start-end dates to the Topic, those dates do correctly appear on the Work-to-Do widget and the Pulse app.
I can even create an event from the calendar page, that appears on the pulse app. I'm just wondering if that's the expected behavior for a Forum.