Am also interested in this. Would be nice for it to notify you of trends (like it does for other items) so you can maybe get a heads up you might be getting sick, but their website very clearly is saying it is for women's health.
EDIT: Just re-read on apple.com. It says: "Apple Watch Series 8 has an innovative new sensor that tracks your temperature while you sleep, so you can see changes over time. Cycle Tracking uses this data to provide a retrospective estimate of when you likely ovulated, which can be helpful for family planning. When combined with your heart rate and logged cycle data, you’ll get a detailed view of your menstrual cycle."
I take this as everyone will get the temp reading while you sleep and changes over time, but that cycle tracking uses it in more detail. So sadly no big benefit, but at least we can see how our temp changes over time.