It's normal in AusE.
Let's say there are social problems (and there are), but no media or politicians are willing to grapple with them. It's quite normal to say, "These problems need to be discussed"; "These problems need to be spoken/talked about."
I would use the first sentence, but they fall on a spectrum. 'Discuss' is close enough to 'talk about' or 'speak about' to pass the sentence as normal, in my opinion.
PS: And "subject, topic, matter, problem" also occur on a spectrum of naturalness.